Introduction: How to determine the relationships among the existing prior design, the accused infringing product and patent involved while the defendant claims the defense of prior design.

Abstract: This case involved the law application relating to the defense of prior design and the similarity determination issue for design. The first and second instance court both compared only the accused infringing product and the prior design, then held the success of prior design defense on the grounds of the established similarity. During the procedure of retrial, the Supreme People’s Court supported our claim, held that whether the defense of prior design succeeds can be determined from comparing solely the accused infringing product with the prior design only in the following situation: the accused infringing product is completely the same as the prior design. Otherwise, if not completely the same, a comprehensive consideration of a group of prior design and the concerned patent is necessary.