The purpose of this study is to identify the factors affecting on increasing of contractors 'profits of EPC projects and also to estimate the impact of each factor on the increase of contractors' profits. For this purpose, a questionnaire based on the components extracted from previous studies was prepared and sent to EPC project experts. At this stage, the factors affecting on profitability of EPC projects were identified according to the PMBOK standard. Then, the opinion of experts on the importance of each of the factors affecting on increasing EPC contractors’ profits was obtained based on the Likert five-choice range and analyzed using SPSS software. The results show that the timely supply of equipment, avoiding of complex administrative bureaucracy, innovation and use of new technologies, adequate expertise and timely financing have the greatest impact on increasing the profits of EPC contractors, respectively.