With high penetration of distributed generation and electric vehicle loads integrated into distribution systems, the safe and economic operation of power system has met an enormous challenge. Based on this background, traditional planning model of distribution system is modified which makes it applicable to the coordinated optimization of distributed generation and electric vehicle charging stations. With the uncertainties of renewable resources represented by time-sequence multi-state models, coordinated allocation model aiming at minimizing total network losses of distribution systems is constructed which subsequently implements an equivalent process on the proposed model through second-order cone relaxation. To verify the effectiveness of proposed model, IEEE 33-bus distribution system is used as the test system. The results demonstrate that the presented method can effectively involve the uncertain characteristic of renewable resources in the coordinated planning problem and thereby meets the practical application requirements.