Abstract: Social impact refers to the adverse impact of a product or behavior on individuals or public institutions by altering how “people live, work, relax, contact socially and organize as members of society”. Construction, maintenance, retrofitting, rehabilitation and demolition of engineering structures generally affect the surrounding population and environment during construction, and especially for those with a greater impact on transport or living environment, the social cost of the adverse social impact may far exceed the actual cost of the project. As one of the three pillars in sustainability assessment, social impact assessment is increasingly considered into the life-cycle design and management of engineering structures. In this work, the origin and development of social impact assessment are summarized, and the social impact categories and stakeholders of construction projects are clarified. Second, two social impact assessment methods, namely the performance scoring method and the impact pathway method, are introduced. The social impact categories and performance reference points in the performance scoring method are sorted out. Furthermore, the social cost indicator system based on the social impact pathway of construction projects is established. Subsequently, the social cost indicators are divided according to the stakeholder categories, with emphasis on the social cost composition and quantification methods of production workplace accident cost, traffic accident cost, traffic delay cost, regional economic loss, loss of living environment quality and loss of public welfare. Finally, the limitations in the social impact identification and cost quantification methods are discussed, and the developments of social impact assessment on construction projects are defined.