Abstract: The article studies the hypothesis and precondition of integrity tenet from the micro mechanism.It analyzes the morals cost of integrity and the drastic conflict between moral tent and the maximization of benefit,with the asymmetric information,in the environment of market economy.According to the article,it is a trial for one's integrity and moral level that the door select which value in the condition of asymmetric information. Researching the morals cost of integrity and the value choice law of the doer in the condition of asymmetric information is advantageous to readily integrity and promote society diapason and stability.