In theoretical circles,the issue of governmental accountability in democratic countries is usually discussed with the precondition of completeness of public indenture.However,the public indenture is actually incomplete.Therefore the institutional arrangement of the governmental responsibility system in democratic countries based on the contractualism must be incomplete inevitably.It is theoretically and practically unattainable to find out the best solution for defining the governmental responsibility in democratic countries currently.A possible way to solve this problem is conducting multiple institutional designs,so as to solve the predicament of government's accountability in the equilibrium of multi-institutions.