Background: Designing the educational package of sexual education based on Iranian culture and study its impact on psychological components in students is great importance. However, no research has ever been done on the impact of sexual education based on Iranian culture on self-concept of adolescent students. Aims: The purpose of this study was to investigate the effect of training package of sexual education based on Iranian culture on self-concept of middle school girl students in Takestan. Method: The research is quasi experimental with pre-test and post-test design with control group. The statistical population of this study is student's middle school in Takestan in 2018-2019 academic year. That Among them 90 students (each group of 45) were selected by multi-stage random cluster sampling and divided into two experimental and control groups. The experimental group received training sexual education in 8 sessions of 90 minutes and the control group did not receive any training during this training period. Data collection instrument was adolescent educational package of sexual education and Rogers Self-Concept Questionnaire (1957). Data were analyzed by the use of covariance analysis. Results: The results showed that training of sexual education based on Iranian culture could be significantly effective in promoting self-concept (p<0/01). Conclusions: Based on the findings of this study, can confirmed the effectiveness of educational package of sexual education based on Iranian culture on self-concept.