This study was conducted in order to prioritize the affecting factors on non-adoption of fish farming in rice fields in Guilan province. This research was conducted in two step in 2009 and 2014 that statistical population were rice farmers of west Guilan province. Sample size in first step of study was 123 farmers who were unwilling to adopt rice and fish mixed cultivation lived neighborhood fields of rice and fish farming. In second step of research, 10% was added to the first step sample size and then 135 people were studied randomly outside the adopters region. The data analysis in first step of research was conducted by multiple response analysis. Also, data in the second step of study was to prioritize using analysis of triangular fuzzy numbers. Result showed that the main limitations for adoption of fish farming in rice fields by farmers were included: absence or lack of security provider organ to prevent of of stealing fish, lack of access to financial services with an emphasis on long-term loans with low interest, rice fields of non-enclosed and problems arising it, the lack of responsible organization for integrated rice-fish farming, Lack of initial funding for the establishment of fish sanctuaries and high costs, Lack of knowledge and information in relationship with rice and fish farming, lack of basic amenities such as deep or semi-deep wells and electricity power, and Long-distance of farmers home from rice paddy.