What evidence do I need to win a trade secrets case in China?

Evidence is the lifeblood of any trade secret litigation in China. Under the Chinese Civil Procedure Law, the party asserting a claim bears the burden of proof — commonly expressed as “who asserts must prove” (谁主张谁举证, shuí zhǔzhāng shuí jǔzhèng). For foreign companies pursuing a trade secret case, the evidentiary burden is particularly heavy because Chinese courts expect comprehensive, documented proof at every stage of the analysis. This FAQ provides a detailed guide to the types of evidence needed, how to collect and present it, and the strategic considerations for building a winning evidentiary record.

The Four Categories of Evidence You Need

To win a trade secret case in China, you must provide evidence across four broad categories:

1. Evidence of the trade secret itself — What the secret is and that it meets the AUCL’s three-part test
2. Evidence of ownership — That your company is the lawful rights holder
3. Evidence of misappropriation — That the defendant acquired, used, or disclosed the secret without authorization
4. Evidence of damages — The economic harm suffered or the defendant’s unjust gains

1. Evidence of the Trade Secret

A. Proving Secrecy (Non-Public Knowledge)

You must demonstrate that the information was not publicly known at the time of the alleged misappropriation. Useful evidence includes:

• Documented creation records — Original development files, research notes, lab notebooks, design specifications, and version control history showing the information was created internally
• Confidentiality designations — Documents marked as “Confidential,” “Proprietary,” or “Trade Secret” at the time of creation
• Access restrictions — Records showing who had access to the information and under what conditions
• Non-disclosure obligations — NDAs signed by anyone who accessed the information, including employees, contractors, and business partners
• Search results — Evidence that the information does not appear in public databases, patent filings, industry publications, or academic literature
• Expert testimony — Industry experts can opine that the information was not generally known in the relevant field

B. Proving Commercial Value

• Financial records — Revenue generated from products or services incorporating the trade secret
• R&D investment records — Documentation of time and money invested in developing the information
• Licensing agreements — Any third-party licenses of the trade secret, demonstrating its market value
• Competitive analysis — Evidence that the information provides a competitive advantage, such as lower costs, higher quality, or faster production
• Internal valuations — Asset valuations, transfer pricing documentation, or board presentations that assign value to the intellectual property

C. Proving Reasonable Protection Measures (Critical)

This is often where foreign companies face the greatest scrutiny. Courts expect to see systematic, documented protection measures. Key evidence includes:

• Written confidentiality policies — Company-wide policies that were communicated to all employees, with acknowledgment receipts
• Employment contracts — Contracts with specific confidentiality clauses that clearly identify what information is considered confidential
• NDAs with third parties — Confidentiality agreements with suppliers, distributors, joint venture partners, and consultants
• Access control records — IT system logs, password protection records, and role-based access permissions
• Physical security records — Locked storage, badge access logs, visitor sign-in sheets, and security camera footage
• Training records — Documentation of confidentiality training sessions, including dates, attendance lists, and training materials
• Exit procedures — Records of exit interviews, return of company property, and reminders of ongoing confidentiality obligations
• Document management systems — Version control, audit trails, and records of who accessed or modified confidential documents

2. Evidence of Ownership

• IP assignment agreements — Contracts in which employees and contractors assigned all intellectual property created during their engagement to the company
• Creation records — Author information, timestamps, and attribution showing the information was created by company personnel within the scope of their employment
• Corporate structure documentation — Evidence showing that the Chinese subsidiary or branch has the right to enforce trade secrets owned by the global parent company, typically through technology licensing agreements or IP cross-border assignment deeds
• Technology transfer records — If the trade secret was developed overseas and brought to China, documentation of the lawful transfer mechanism must be maintained

3. Evidence of Misappropriation

This is typically the hardest category to prove, as direct evidence of theft is rare. Courts accept both direct and circumstantial evidence.

Direct Evidence

• Witness testimony — Colleagues who saw the defendant copying files, photographing documents, or accessing restricted areas without authorization
• Electronic evidence — Computer access logs showing unusual or unauthorized access to trade secret files, USB insertion records, email forwarding of confidential documents, or cloud upload activity
• Physical evidence — Photographs, video surveillance, or stolen documents in the defendant’s possession
• Confessions — Written or recorded admissions by the defendant

Circumstantial Evidence (Often Equally Important)

• Timing — Suspicious timing between the defendant’s departure from your company and their new employer’s launch of a competing product or service
• Access — Evidence that the defendant had access to the trade secret in their previous role
• Substantial similarity — Expert analysis showing that the defendant’s new product, process, or business method is substantially similar to your trade secret, especially where independent development would be unlikely
• Inability to independently develop — Evidence that the defendant or their new employer lacked the resources, time, or expertise to develop the information independently within the relevant timeframe
• Lack of independent records — The defendant cannot produce development records, research notes, or other documentation showing independent creation

4. Evidence of Damages

• Lost profits — Financial records showing a decline in sales or revenue attributable to the misappropriation
• Price erosion — Evidence that the defendant’s use of the trade secret forced the company to lower prices
• Defendant’s profits — Financial records showing the revenue and profit the defendant earned through use of the trade secret
• Royalty benchmarks — Evidence of what a reasonable royalty for licensing the trade secret would have been in a hypothetical negotiation
• Corrective costs — Expenses incurred to mitigate the damage, such as developing alternative processes or rebranding products

The 2019 Burden-Shifting Mechanism

One of the most important changes in the 2019 AUCL amendment is the partial shift of the burden of proof. If the rights holder provides 初步证据 (chūbù zhèngjù, preliminary evidence) that:

• They have taken reasonable protection measures, AND
• The defendant’s information is substantially similar to the trade secret, AND
• The defendant had access to the trade secret or a reasonable probability of acquiring it

Then the burden shifts to the defendant to prove that they did not misappropriate the trade secret. This is a significant advantage for plaintiffs, but it requires strong preliminary evidence to trigger the shift.

Evidence Preservation: 证据保全 (zhèngjù bǎoquán)

If you fear that evidence may be destroyed, hidden, or tampered with, you can apply to the court for an evidence preservation order before filing the lawsuit. The court will send judicial officers to the defendant’s premises to seal and secure relevant documents, electronic devices, and records. To obtain this order, you must:

• Demonstrate an urgent risk of evidence destruction
• Provide a preliminary description of the evidence to be preserved
• Offer security (a bond or deposit) to cover potential damages if the preservation is ultimately found unjustified

Practical Evidence Checklist for Foreign Companies

Notarization and Authentication Requirements

Evidence originating outside China requires special handling:

• Foreign public documents must be notarized in the country of origin and then authenticated by the Chinese embassy or consulate (or apostilled if the country is a Hague Convention signatory)
• Foreign private documents (contracts, emails, internal records) generally require notarization of the signatory’s identity and may require additional authentication
• All foreign-language evidence must be accompanied by a certified Chinese translation
• Electronic evidence should be preserved through notarization (公证, gōngzhèng) by a Chinese notary public to establish authenticity and chain of custody

Common Evidentiary Mistakes

1. Relying on oral testimony alone — Chinese courts give much less weight to oral testimony than common law courts. Written documentary evidence is far more persuasive.
2. Submitting evidence after the deadline — Chinese courts set strict deadlines for evidence submission. Late evidence may be rejected.
3. Insufficient specificity — General claims that “proprietary information” was stolen, without identifying the specific information and proving its trade secret status, will fail.
4. Failing to preserve electronic evidence properly — Screenshots alone are weak evidence. Electronic evidence should be preserved through notarization or forensic imaging to establish authenticity.
5. Not using the burden-shifting mechanism — Many foreign plaintiffs fail to present the preliminary evidence needed to shift the burden to the defendant, missing the opportunity to make the defendant prove their case.
6. Ignoring the translation burden — Submitting hundreds of pages of English-language documents without certified Chinese translations can delay the case significantly.

Conclusion

Winning a trade secrets case in China requires comprehensive, well-organized, and properly authenticated evidence across four categories: the nature of the trade secret itself, ownership, misappropriation, and damages. The 2019 AUCL amendment’s burden-shifting mechanism provides a powerful tool for plaintiffs who can present strong preliminary evidence, but the initial evidentiary burden remains substantial. Foreign companies that invest in robust protection measures, maintain meticulous records, and engage experienced Chinese counsel at the earliest sign of a breach will be best positioned to meet their evidentiary obligations and succeed in Chinese trade secret litigation.

Last updated: July 2026. This article provides general guidance and does not constitute legal advice. Foreign businesses should consult with qualified Chinese legal counsel for case-specific recommendations.

Official Sources

• China National Intellectual Property Administration: Trademark Law
• China National Intellectual Property Administration: official service portal
• World Intellectual Property Organization: China legal and treaty resources