Human Resource Management includes the processes to access the best utilization of people that involves in the project-based organizations. Timely delivery of projects, eliminating the gap between the actual performance of the project and project objectives, eliminating skills shortages in the organization and minimizing the costs of human resource management are the challenges of human resource management. This research investigates a new concept of human resource management in project-based organization by using system dynamics method and based on "An, Jeng, Lee and Ren"’s method submitted in 2007. Their model considers interaction between supply side and demand side of human resource management in project based organizations. The structure of the proposed model in this research considers effect of Performance of human resource management and Projects cost on supply side and demand side of human resource management in project based organizations. According to dynamics of project problems, to understand and improve treatment of complex projects, system dynamics approach will be used. System dynamics approach focuses on the dynamic interaction between the components and the dynamic behavior of systems and has analytical ability to process information of project-based organizations. The model presented in this thesis has the following strengths: