Irritable bowel syndrome (IBS) is one of the most common gastrointestinal disorders. Approximately 10-20% of adults & adolescents have symptoms consistent with IBS. Half of the patients with IBS have psychiatric disorders, including depression, panic disorder, generalized anxiety disorder .High level of stress, concern and anxiety lead into the low quality life and using inefficient coping skill. The present study aimed at the importance of effectiveness of new psychological therapies in IBS and the comparison of its effectiveness with the most common IBS psychological therapy, cognitive-behavioral therapy and the effectiveness of these two types of therapies in reduction of symptoms and improvement of life quality based on coping skills of the patients with IBS. 36 subjects were selected by convenient sampling and after determining the type of coping skills (problemfocused-emotion-focused) were randomly divided to experiment and control group. Demographic questionnaire and ROMEIII Criteria were used to indicate the characteristics of patients and the severity of IBS. Two Cognitive-behavioral therapy (CBT) for IBS patients and Mindfulness therapy (MFT) were applied for IBS patients. In two treatment groups, the mean general scores of life quality in post-test and follow up had great changes in comparison with pre-test. The number of the subjects in pre-test was similar in terms of the type of coping skills in three groups but the emotion-focused subjects were decreased in post-test in both types of therapy and problem-focused patients were increased. Among two therapy methods, Mindfulness-based method is more effective in increasing the life quality and reduction of clinical symptoms of IBS compared to cognitive-behavioral therapy (P<0.05). The results showed that although there was a significant difference between two therapy methods and two types of coping skills in reduction of clinical symptoms and increasing the life quality of the patients with IBS, there is no interaction between therapy methods and the type of coping skills. The results showed that Mindfulness-based therapy was more effective in reduction of the symptoms and life quality in follow up stage compared to cognitive-behavioral therapy method. Thus, besides the efficacy of mindfulness-based therapy at the end of the therapy, it had long-term effects compared to behavioral-cognitive therapy.