The purpose of this study was Study of effectiveness cognitive behavior therapy on decrease rage of depression and quality of life adult’s age women. The present research was experimental using pre-posttest follow up and control group. The sample consists of adult’s age women with depression symptoms that have referred to counseling centers in Bushehr state. Sampling method was accessible whit randomly in the population. Thus the by using GDS-15 and WHOQOL questionnaires in this research 70 adult’s age women that Were eligible for study identify and among them 46 adult’s age women were chosen randomly and assigned to two groups randomly (23 member in the experimental group and 23 member in the control group). We administered 8 weekly sessions of 45 minutes of cognitive- behavioral therapy for experimental group, but the control group didn’t receive any intervention. A week after the end of intervention, post-test was performed in the studied variables and after three month the follow-up test was performed. In order to analyze the resulted data, MONCOVA analyzing method is used along with SPSS16. The outcomes of the MONCOVA analyzing showed that there were a significant difference between depression and quality of life in control and experimental groups (p<0/01). And the cognitive behavioral group therapy intervention reduces rage of depression and increases the quality of adult’s age women)