Abstract: In the past 30 years or so， the power structure of giant departments decisionmaking， implementation and supervision (triplepower structure for short) in the executive agency model has taken on a new form， which is represented as the development of autonomous networks in the horizontal dimension， and the hierarchical supervision and control over executive agencies autonomy by decisionmaking and supervision powers of core departments in the vertical dimension. There are four static types of power structure for integrating hierarchy and networks—networks in hierarchy， coexistence of hierarchy and networks， hierarchies as the nodes of networks， and political hierarchy structure for controlling networks. The dynamic mechanisms of integrating hierarchy and networks are realized in the process of exercising decisionmaking powers， executive powers and supervision powers.

Key words: executive agency, giant department, triplepower structure, network, hierarchy