Background and Purpose: Academic conscientiousness is the best predictor of personality for professional, educational, and academic performance. Therefore, the purpose of this study is to provide a model of academic conscientiousness based on social adequacy through the mediation of academic engagement in female high school students. Method: The method of this research was descriptive-correlational modeling of structural equations. The statistical population includes all-female high school students in Bukan County (N = 1400) who were studying in the 2019-2020 academic year. The sampling method was multi-stage cluster. The sample size was 300 participants. For data collection, McIlroy and Banting’, s Academic Conscientiousness Questionnaire (2002), Academic Adequacy Questionnaire (Felner et a, 1990), and Fredricks, Blumenfeld, and Pari’, s School Engagement Questionnaire (2004) were used as assessment tools. Data analysis was performed by Pearson’, s correlation method and structural equation modeling by using the SPSS 23 software and LISREL 8. 8. Results: Findings showed that the direct path of social adequacy to academic conscientiousness (β,= 0. 45, p <0. 001), academic engagement to academic conscientiousness (β,= 0. 60, p <0. 001), academic engagement to social adequacy (β,= 0. 63, p <0. 001) and the indirect path of social adequacy to academic conscientiousness mediated by academic engagement (β,= 0. 42, p <0. 001) were positive and significant. Fit indices equal to CFI = 0. 97, NFI = 0. 95, FIFI = 0. 93, AGFI = 0. 90, RMSEA = 0. 074, p = 0. 001, which shows that the assumed model had a relatively good fit with the data. Conclusion: Based on the results obtained, social adequacy was directly and indirectly related to academic conscientiousness through academic engagement, and social adequacy and academic engagement can be a good predictor of academic conscientiousness. The results of this study contain important practical implications for improving students' academic conscientiousness.