Abstarct: Purpose: The purpose of this study was to investigate the effect of aerobic exercise training on the serum levels of anandamide and depression index of female students with depression disorder. Materials and Methods: this study was a clinical trial with pre- and post-tests. Subjects were selected by referring to the consultation center of the university from among a list of depressed students. Contacting them, students who expressed their consent to participate and had a Beck depression score >۱۷, entered into study. The subjects (n=۲۴) assigned into two experimental (n=۱۲) and control (n=۱۲) groups, randomly. The experimental group performed aerobic training for ۶ weeks, ۳ sessions a week at %۶۰-۸۵ of their maximal reserve HR. The control group followed their routine life. The subjects’ blood samples were taken at ۸ a.m. after fasting for۱۰- ۱۲ hours both before and after completion of training program. Data were analyzed using of ANOVA and Paired T-tests. Results: there was no significant difference in BMI after ۶ weeks aerobic training compared to control group (p=۰.۲۳). there was no significant difference in body fat percent after ۶ weeks aerobic training compared to control group (p=۰.۸۷). there was no significant difference in anandamide serum levels after ۶ weeks aerobic training compared to control group (p=۰.۶۳). depression index and VO_۲max improved significantly after ۶ weeks aerobic training compared to control group (p=۰.۰۰۲, p=۰.۰۰۷, respectively). Conclusion: the results of this study showed that ۶ weeks aerobic exercise training leads to no significant change in serum levels of anandamide of depressed girl students. However, it improved depression index and aerobic power significantly.