[Jian Xu] "Hard" and "Soft" evidence in Chinese patent invalidations

We usually classify evidence for patent invalidation in China into two types:

(a) “hard” prior written publications, which usually includes prior patent publications and recognised scientific/technical journals worldwide, ideally prior patent publications, and

(b) “soft” prior use evidence, which shows the product was available on the market earlier, and usually includes various sales/promotion type of documents/testimonies worldwide, e.g. product leaflets, manuals, sales contracts, invoices, advertisements, user/manufacturer testimonies.

Both “hard” and “soft” evidence can be used to argue patent invalidity. However, in Chinese practice, the petitioner must be strong on “hard” evidence in order to have any chance of winning in the patent invalidation proceeding. It is extremely rare for any patents to be declared invalid based solely on “soft” evidence. This is because the Chinese courts and patent office, unlike those in the west which emphasize experts and cross examination in patent litigation proceedings, inherently distrust the testimonial/circumstantial type of evidence (i.e. soft evidence), but very much prefers paper evidence whose authenticity can be easily verified through official/formal channels (i.e. hard evidence).