In the recent decades, electricity energy consumption has increased as population increased, and technology and human’s life style are improved. Over the past century, electrical energy consumption has doubled almost every eight years. Almost everywhere around the world, large power plants have been constructed and transmission grids connected the load centers to the generation points as a meshed grid. To overcomethe mentioned load increases, new power plants should be built or the existing plants,as well as transmission and distribution systems, should be expanded. According to the literature, Distributed Generation (DG)resources could have several benefits which if it used properly, their disadvantages would be dominated by their advantages.Optimum sizing and siting of DGs is the key point in installation and operation of these resources. In power system studies, to decrease complication and computation, and sometimes to consider the worst case, power consumption is considered as consonant load (PQ constant).On the other hand,loads’ consumption is a function of voltage and frequency of the supply. Therefore, load modeling can lead to a more accurate study and result. In this research, sizing and siting of DGs is discussed as a two-dimension multi objectives problem while static load modeling is taken to account. To do so, at the first step, the objective function consists of only technical indices and in the next case also includes economic indices, and the problem is introduced and solved as an economical or technical multi objective problem. At the second step, two technical and economical objective
