This study treats large and complex project organization as a dynamic and complexrelated social network.An analysis was made of the difference of project management concepts from social and traditional perspectives and the organization network model factors of large and complex projects by social network analysis (SNA), meanwhile,a study was made of the related basic models and modeling methods.The related model was established based on empirical analysis of Expo 2010 Shanghai.Based on the calculation and analysis with Ucinet software as well as a comparative study with traditional formal organization structure,the paper presents the conclusion and suggestions on organization management and control.