Abstract: It is of special significance to re-examine the role and function of the board of directors in Chinese corporate governance when the unitary corporate governance structure is introduced in the revised draft of company law. Facing the long-term confusion of the board of supervisors system and the practical problems of overlapping and hollow supervision in the mixed mode, the Monitoring Board emerges in the background of the widespread phenomenon of agency sinking in China. Compared with the traditional board of directors, the Monitoring Board takes its supervision function as the core in corporate governance. Especially in the default of the board of supervisors system in unitary corporate governance structure, it plays a role as the supervision organ of the company. In the guarantee of the independence of the subject and the comprehensiveness of the object, the board of directors under the new structure will be able to achieve flexibility and depth of supervision. It is conducive to bringing into full play the supervision function of the board of directors to construct a selection and appointment mechanism to strengthen the voice of the vulnerable shareholders, an exercise of power mechanism to guarantee the rival power of the supervisory subject, an innovative and diversified incentive mechanism and an investigation mechanism consistent with power and responsibility, in order to promote the benign development of corporate governance practice and modern corporate system in China.