Abstract: Leniency program is an important instrument in the system of public enforcement of antitrust law. Its basic element is granting some form of leniency to corporations or individuals who report their illegal antitrust activities and cooperate with the public enforcement institutions if they meet certain specified conditions of the program. In the U.S. legal practice，corporate leniency policy，leniency policy for individual，amnesty plus，penalty plus，as well as the traditional tool of plea bargaining，interrelate with each other and work together，and have become an extremely powerful weapon for public enforcement institutions in the antitrust game and significantly contribute to the realization of the value of public antitrust enforcement for achieving optimal deterrence. Drawing upon the legislative and judicial experience of U.S. leniency program，China could formulate laws of general applicability to improve and refine the specific rules of its antitrust leniency program，and at the same time make corresponding adjustment to relevant provisions of other components of the public enforcement system，which is of particularly important practical significance.

Key words: leniency policy, amnesty plus, penalty plus, public enforcement, optimal deterrence