On time supply of materials in construction projects is very important. Therefore, coordinating a project with key suppliers, while ensuring the timely supply of materials, make the minimum costs of project. One way to create this coordination is integrated inventory planning which has been accomplished in this study. It is necessary to mention that such a model is considered NP_hard in terms of complexity class, because the model is compound of the inventory planning and planning with limited resources, that in literature, the class of programs with limited resources is considered NP_hard. Therefore, in this paper while introducing the inventory planning model in project supply chain, a model based on genetic algorithm is proposed to determine the solution. The proposed algorithm has been run for the suitable size problem and the results show that the introduced algorithm, in actual sizes, within a reasonable time, provides an appropriate response.