Based on the social cognition theory, this study uses 312 valid employee questionnaire data to explore the effects and mechanisms of social class on employee organizational justice. The results show that: social class and employee"s organizational justice are significantly positively correlated; Internal attribution tendency plays a mediating role in social class and organizational justice; relative deprivation moderates the indirect effect that social class influences the organizational justice through internal attribution tendency. For employees with low relative deprivation, the social class influences the organizational justice through the cognitive path of internal attributional tendency.