Comparing Patent Infringement Litigation: China vs. United States - Pleading Standards And Discovery In Patent Cases

The Highlights

1. Procedural Initial Requirements in China: In China, initiating a patent infringement lawsuit necessitates plaintiffs to present extensive and comprehensive evidence of infringement with the initial complaint due to the absence of a formal discovery process.
   
   
2. Lower Pleading Standard in the U.S.: The U.S. patent litigation system requires a lower threshold for initial pleadings, often allowing cases to proceed on the basis of good faith allegations, with detailed evidence being developed during the extensive discovery process.
   
   
3. Strategic Implications: The procedural contrasts between China and the U.S. influence litigation strategies, where China's system mandates thorough preparation upfront while the U.S. system relies on discovery, impacting both the cost and duration of litigation.

Patent infringement litigation varies significantly across jurisdictions--especially between China and the United States. For multinational companies, legal professionals, and inventors seeking to protect their intellectual property, understanding these differences is critical. 

Recently, a client from China asked for the preparation of a new lawsuit, and when we provided the draft complaint for the new lawsuit, the legal team in China asked why the draft complaint contained only limited details of the infringement – essentially, only good faith allegations. The legal team in China was surprised that such a “barebones” complaint was sufficient, noting that it did not include detailed infringement mappings, with presumptive rebuttals of both non-infringement and even potential invalidity positions. The legal team in China was well versed in Chinese patent law, and Chinese patent litigation, but it had never litigated before in the U.S. We provided some explanation of the differences in the two systems, and this short article resulted.

Patent Infringement Complaints in Chinese Courts 

In China, initiating a patent infringement lawsuit requires plaintiffs to present a comprehensive and specific infringement contention at the very beginning of the case. Plaintiffs are expected to submit, with the initial complaint:

• Evidence demonstrating that the defendant has infringed the patent right, such as a comprehensive infringement mapping¹;
• Evidence of the infringing act (e.g., sales webpages, promotional brochures from trade shows); and
• Evidence supporting the amount of damages claimed (e.g., sales records).

This rigorous requirement is a direct result of China's lack of a formal discovery process. Because parties cannot compel production of documents or testimony from their opponent, courts rely heavily on the initial filings to determine whether the case has merit and should proceed.

In patent infringement litigation in China, as in most civil cases, the burden of proof generally rests with the plaintiff. This principle is affirmed in Article 2 of the Chinese Supreme Court's Interpretation on the Rules of Evidence in Intellectual Property Litigations. Plaintiffs must present compelling evidence to support their claims from the outset, which shapes the way cases are prepared and filed in Chinese courts. As such, throughout the subsequent trial proceedings, the plaintiff typically independently collects and prepares all evidence required to prove infringement and damages.² 

In specific cases, such as cases involving new product manufacturing methods, the court may shift the burden of proof to the defendant once the plaintiff makes a sufficiently persuasive prima facie showing. Even so, plaintiffs in a Chinese court are strongly incentivized to assemble robust and comprehensive evidence at the outset, as there is limited opportunity for further evidence gathering once the case is underway.³

The U.S. Approach: Lower Pleading Threshold and Extensive Discovery 

The U.S. system takes a different approach to pleading standard, based primarily on the availability of discovery. And, in the U.S., the threshold for the pleading stage in patent infringement cases is relatively low, compared to the threshold of Chinese patent cases.

In the U.S., plaintiffs are not expected to produce evidence at the outset. Instead, the pleading standards set by the U.S. Supreme Court in Bell Atlantic Corp. v. Twombly, 550 U.S. 544 (2007) and Ashcroft v. Iqbal, 556 U.S. 662 (2009) only requires the complaint to state a “plausible” claim. In patent cases, this means that the complaint must contain “factual allegations that, when taken as true, articulate why it is plausible that the accused product infringes the patent claim. AlexSam, Inc. v. Aetna, Inc., 119 F.4th 37, 35 (Fed. Cir. 2024). Depending on the complexity/materiality of an element to practicing the asserted claim, the complaint can even omit some claim elements. Id.   

This comparatively lower threshold, as contrasted with the system in China, is balanced by the U.S. legal system's broad discovery process, which allows parties to use the discovery to obtain and exchange evidence before finalizing their infringement or invalidity contentions. F.R.C.P. Rule 26. Discovery enables both sides to request documents, depose witnesses, and gather information that may be critical to proving—or disproving—infringement. The plaintiffs can also amend pleadings in light of findings from the discovery with leave of court. Because discovery plays such a central role, U.S. complaints often begin with less detail, with the expectation that critical evidence will emerge during litigation. 

Practical Implications for Litigants 

These procedural differences carry significant strategic consequences:

• China requires plaintiffs to put forward a complete and well-evidenced case at filing. This deters weak claims but can disadvantage plaintiffs lacking access to internal information held by defendants.
• The United States permits cases to begin with more limited information, essentially good faith allegations, enabling plaintiffs to rely on discovery——but this can also lead to longer and more expensive litigation.

For accused infringers, this difference in systems means that early defenses in China focus on attacking the sufficiency of the initial evidence, but U.S. defendants cannot generally ask for immediate case resolution, as the discovery process must occur first.

Conclusion 

Effective global patent enforcement requires tailoring litigation strategy to each jurisdiction's procedural framework. China's front-loaded system demands comprehensive infringement evidence at filing, while the U.S. system permits cases to proceed with minimal initial detail—relying on discovery to develop the factual record. 

For companies operating internationally, recognizing and adapting to these differences is essential to protecting intellectual property and managing litigation risk. 

Footnotes

1. See, for example, Appendix 2: infringement mapping, page 397 of The Template of Pleadings, The Supreme People's Court of the People's Republic of China, https://www.court.gov.cn/fabu/xiangqing/468671.html,  https://www.court.gov.cn/upload/file/2025/06/22/17/43/202506221742_01.pdf;

2. See, for example,  http://gongbao.court.gov.cn/Details/517a2b30803250a76e2c6116325328.html?;

3. See, for example, Article 66 of the Chinese Patent Law, addressing this burden-shifting mechanism for new product manufacturing methods; https://www.cnipa.gov.cn/art/2020/11/23/art_97_155167.html; and, also see, for example, Article 3 of the Supreme Court's Interpretation, stipulating that, under certain circumstances, the burden of proof may also shift in cases concerning manufacturing methods of existing products,  http://gongbao.court.gov.cn/Details/517a2b30803250a76e2c6116325328.html. 

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.