Distributed generation (DG) is more and more installed and integrated in the electric power systems, mainly in distribution networks. The conventional method of voltage control with on-load tap changer transformers is not efficient enough to deal with the growth of integration of distributed generators. The DG power regulation will contribute to optimize the steady voltage profile in network and thus to rise the maximal DG installation capacities of network. The work reported in this paper shows that the coordination of DG power regulation can realize a voltage control of distribution network. The coupling between active power and voltage magnitude must be taken into account according to the our results.