Trial is a highly routinized and institutional activity, in which all the participants have the clear knowledge about their role and power, and there are also complicated goal relationship among the participants. Although there are various non-compliances of the Cooperative Principle and obvious noncooperations in trials, judges, prosecutors, and lawyers who have the speech power will force the litigant to cooperate, making the trids go back to normal, and thus achieve the cooperation at the macro level.