The American interest group interacts with administrative agencies in the American policy system, and their mode of the political interactions is the iron triangle, and policy liaison network mode, which is much more complex. Both modes have led to the legislative, judicial and executive powers that are more inclined to cooperate with each other instead of mutual restraints, in order to distribute the advantage of the political system of separation of powers. Meanwhile, the two modes have experienced more competitions, which is not in favor of the overall operations of the policy-making process.