Purpose: The aim of this study was to predict Predicting flourish in female adolescents by maternal character strengths: the mediating role of emotional regulation. Methodology: This was an applied study conducted based on a descriptive-correlational design. The statistical population consisted of 3996 secondary high school students from Rey city during the academic year of 2018-2019. For sample size, a total of 350 students were chosen according to Kerjcie and Morgan’s table and using multi-stage cluster sampling. Research tools included an actualization questionnaire developed by Soleymani et al. (2015), Seligman and Peterson’s character strengths questionnaire (2004), and emotion regulation questionnaire (Gross and Jhon, 2003). The reliability of questionnaires was confirmed by professors and their credibility by Cronbach’s alpha (α = 0.85). Data were analyzed through correlational tests and structural equations in Spss24 and Amos20. Findings: From the results, maternal character strengths directly (by a path coefficient of 0.65) and indirectly (through emotion regulation; with a Path coefficient of 0.21) influences girl’s actualization (p<0.001). Also, emotion regulation affects actualization with a Path coefficient of 0.58. Research variables predicted 51 % of the variance of secondary high school girl’s actualization (R2=0.51). Conclusion: Education and empowering character strengths, as well as regulating maternal emotions, improves girl’s actualization
