On the assumption that between independent directors and shareholders were agency relationship, three variables including independent directors' moral level, individual ability, information transmission mechanism were introduced which were based on the corporate governance mechanism allocation of powers, counter balance and the theory of incentives. Independent directors were risk neutral, then the company revenue maximization was equivalent to the effectiveness maximization of independent directors. All the shareholders made agreement on the selection of independent directors. Managers would damage the interests of shareholders without supervision of council. Independent directors were economic-beings that would maximize their own effectiveness. The mathematical models of operational mechanism were built by using output function, cost function and profit maximization. Through the analysis on mathematical model the result of Chinese independent director system operational mechanism was explained and tested.