Abstarct: Human resources are one of the most important and valuable assets of an organization, and Organizations cannot achieve success without quality and efficient staff. Today, the horizontal structures of organizations and the smooth process of people's work-life make it less possible for individuals to benefit from their full potential and it creates a context for people's career plateau, and therefore an obstacle to the advancement of organizations. Therefore, in this study, the effect of social intelligence on career plateau reduction with the mediating role of psychological capital was investigated. The method of this research was applied in terms of purpose and in terms of nature and method, it was descxriptive-correlational. The statistical population of the study consisted of the staff of the Golestan Province Gas Company's headquarters and 109 employees. Using simple random sampling, the sample size was 85 employees. The questionnaire was the most important research instrument and the method of data collection was field and library. SPSS and Smart PLS software was used for data analysis. The results showed that social intelligence and psychological capital had a significant and inverse relationship with career plateau. Social intelligence has a direct and positive impact on the psychological capital of employees. In other words, increasing the level of social intelligence and psychological capital among employees can reduce career plateau.