The purpose of this research is to investigate the participation of citizens in urban affairs and its ranking among people aged 18 and older in this city. The current research is descriptive and survey-type, the statistical population of the research is made up of all residents of Sari city .The sample size is 700 people,which was selected by multi-stage cluster sampling in proportion to the size of the city of SariA questionnaire was used to collect the data, and TOPSIS fuzzy technique was used to analyze the data Based on the findings of the research, especially the competitiveness coefficient, it is found that the citizens of Region 3 ranked first in terms of participation and its criteria with an index of 0.946654. And the citizens of region one with an index of 0.293544 and region two with an index of 0.204235 took the second and third place, respectively, and it is noteworthy that the difference between the participation of the citizens of region one and the other two regions is significant. According to the calculations of Shannon's entropy, among the participation evaluation criteria, the index of monitoring activities has the highest dispersion, which indicates the greatest importance and weight among other indicators of participation. In general, it can be said that the citizens participated the most in the monitoring activities index and the least participation in the city administration index, which shows the tendency and cooperation with the municipality and the city council, which has the least importance and weight.