Crop marketing has an important role in accomplishing goals such as agricultural development, production increase, and enhancement of farmers’ income in developing countries. Citrus production, especially sour lemon, is one of the most important productions in Larestan County, Fars province in Iran. So, the determinants of the sour lemon marketing system improvement were prioritized in Larestan in this study using Analytic Network Process (ANP) in which data were collected through a questionnaire filled by experts in the region. Criteria were the 4Ps (Product, Place, Promotion, and Price) in the marketing mix and here were also some sub-criteria for each of the criteria. The criteria and sub-criteria were chosen based on other studies and also experts’ views in the region. Results showed that product and promotion criteria had the first and last priorities in improving the sour lemon marketing system in Larestan County, respectively. In addition, proper packaging and designing to create a competitive advantage was the most important sub-criterion for improving the sour lemon marketing system in the region. Also, the creation of processing industries and using marketing cooperatives were the next most important sub-criteria, respectively. According to the results, it is suggested to develop proper packaging, processing industries, and marketing cooperatives in the region.