Abstract: In order to explore the factors affecting the environmental citizenship behaviors in major water conservancy projects, based on the planned behavior theory, institutional pressure and environmental responsibility perception were introduced to build a structural equation model of influencing factors.Through a questionnaire survey involved 242 project staffs in major water conservancy projects, SPSS and AMOS were used for model inspection.It is found that institutional pressures have a positive impact on the environment citizenship behaviors through the intermediary role of attitude and perceptual behavior control, and the mediating role of perceptual behavior control is stronger.Perceived environmental responsibility positively moderates the relationship between normative pressures and attitude, and it also positively moderates the relationship between mimetic pressures and perceptual behavior control.This paper enriches the 'institutional-psychological' mechanism of major water conservancy project members' environmental citizenship behaviors, and provides a reference for effectively improving the environmental management performance in major water conservancy projects by using institutional power.