This paper comprehensively analyzes several factors that influence the charging station planning for electric vehicles， and then an income optimization model of charging station planning for electric vehicles is developed. In order to meet the capacity requirement of charging station in the planning area， the electric vehicles expected power demand is calculated based on the charging characteristics and trip characteristics of electric vehicles. The weights of Voronoi diagram are adjusted to make the service areas divided more rationally and the load rate better balanced based on the distribution characteristic of electric vehicles. Combining the weighted Voronoi diagram， the global searching ability of the particle swarm optimization algorithm is used to locate and size the charging stations and optimally plan the service areas. By calculating different numbers of electric vehicles and different ways of distribution， the results verify the effectiveness and feasibility of the proposed model and algorithm.