The core of management in a group company is its control of subsidiaries and the cooperation between subsidiaries. The control shows up in the longitudinal power disposition in order to realize strategic alignment; the cooperation shows up in the transverse concerted action in order to realize complementary effect and synergistic effect. This paper aims to discover the connotation of control and cooperation, their functions, the way to realize them and the relationship between them in a group company. The control assures the realization of cooperation and cooperation needs control. In practice, to select the right control point and cooperation point can realize the control of contingency and cooperative operation in a group company.