Background  and  Purpose: The  purpose  of  this  research  was  to  investigate  the  effectiveness  of  dialectical behavior therapy on depression symptoms and emotion regulation of self- injury Adolescents.
 Method: This study was a quasi-experimental study with a pre-test and post-test design with a control group. All secondary school male students of the second period in the academic year 1402-1403, who had referred to Hamraz Educational Counseling Center in Gorgan city due to self- injury behaviors, 24 of them were randomly selected by available sampling method in two experimental groups and were controlled. The experimental group was trained in dialectical behavior therapy in 8 sessions of 90 minutes as a group, and the control group did not receive any
intervention. The research tools included Beck's (1961) depression questionnaires and Garnevsky et al.'s (2001) cognitive emotion regulation questionnaires. The data were analyzed using multivariate analysis of covariance test.
Results: The results of the present research showed that dialectical behavior therapy is effective in improving the symptoms of depression and emotional regulation of self- injury Adolescents. Also, dialectical behavior therapy is effective in improving compromised and compromised emotional regulation strategies of self- injury Adolescents.
Conclusion: Based on the findings of the present research, dialectical behavior therapy can be used as an effective approach to the symptoms of depression and emotion regulation of self-injury Adolescents by using the techniques of distress tolerance and acceptance, emotional self-regulation, mindfulness, and effective communication.