Since the birth of U.S.antidumping laws,they have been closely connected with the domestic trade protection demand in different developing stages.In particular,they have turned into the main forces of import regulation in modern time.The analysis on the U.S.antidumping laws' origin of abandoning the anti-trust mode and following the idea of regulating the antidumping through administrative powers would help to reveal the inedibility of the role of the U.S.antidumping laws in the trade protection.