Background & aim: The emotional schema model emphasizes on evaluation and interpretation of anxiety symptoms and emotion regulation strategies. The present study aimed to determine the effectiveness of Emotional Schema Therapy (EST) on anxiety sensitivity and emotion regulation strategies. Methods: The present research was a semi-experimental study with a pretest-posttest control group. The statistical population of the present study was adolescent girls with social anxiety disorder who were studying in the high schools of Delfan, Iran, during the academic year 2016-2017. For this purpose, 32 students with clinical symptoms of social anxiety were selected with screening method and were randomly assigned to experimental and control groups. The Social Phobia Inventory (SPIN) with clinical interviews were used for screening, the Anxiety Sensitivity Index (ASI) and Emotion Regulation Questionnaire (ERQ) were used to collect data in two conditions (pretest and posttest). then, the experimental group participated in the main intervention process of emotional schema therapy, which was directed by a PhD student of psychology in 10 sessions of 90 minutes, while the control group received no treatment intervention. Data were analyzed using SPSS software (ver 23) and multivariate analysis of covariance (MANCOVA). Results: The results showed that in the experimental group in the post-test phase compared with the control group, the mean scores of anxiety and emotional regulation suppression were significantly decreased (P <0.001) however, the mean scores of the emotion regulation Was significantly increased (P <0.001). (Use numbers and figures in the findings. Conclusion: The study findings proposed that emotional schema therapy can be used as an effective intervention in order to reduce symptoms of social anxiety and improved emotion regulation strategies in the people with clinical symptoms of social anxiety.