The purpose of this study is to investigate the effectiveness of teaching metacognitive strategies by storytelling method on improving the courage of sixth grade students in Nowshahr. The research method was quasi-experimental and the statistical population included all sixth grade students in girls' schools in Nowshahr in the academic year 2020-21. The statistical sample consisted of 50 subjects who were selected by random sampling method and were placed in two experimental and control groups. To determine the level of students' assertiveness, Gambrill and Ritchie(1975) Assertiveness Questionnaire was used as a data collection tool, which reported a validity coefficient of 0. 39 to 0. 70 and a reliability of 0. 86. First, the subjects of both groups were pre-tested and then the experimental group participated in 10 sessions (90 minutes) of teaching metacognitive strategies by storytelling method. Subjects were retested after the sessions. Analysis of covariance using SPSS21 software was used to analyze the data. According to the research results, it can be concluded that teaching metacognition strategy with storytelling method has a significant effect on improving the courage of sixth grade students in Nowshahr, so it can be predicted that the generalization of this training can have a positive effect on other aspects of life.