Abstract: The article reviews the American case law on the virtually identity rule in the contextof determining whether copyright infringements exist, summarizes its origin, development andstandardization, mechanism; clarifies the feasibility of the rule applied by Chinese courts directlyand subjective and objective efforts be made when application; makes comments on the retriajudgment of Zheng Baocheng case.

Key words: Copyright Law Copyright infringement Virtually identity rule Substantial similarity rule