Anti-circumvention measures are emerging trade tarif in international trade and an extension and development of anti-dumping measures. 2005 saw the application of the rule of minor alternation and later development in U.S. anti-circumvention law against China' s export products in paraffin candle case for the first time，while American exported optical fiber relating to minor alternation and later development was not sanctioned ef ectually aft er being imposed anti-dumping duties by China in the same year. Therefore，it is practically signifi cant and imperative for China to bring forth operational anti-circumvention legislation.