Due to the importance of the issue of audience aggression in stadiums, many researches have addressed this issue. The purpose of the present study is to investigate the effect of team identity on the aggressiveness of football spectators. The statistical population of the research included all football spectators across the country. Also, the size of the statistical sample was considered to be 384 people based on Morgan's table. The method of collecting the data of the research was in the field and using the preparation and distribution of a questionnaire that included three parts: "demographic characteristics", "determining the level of fans' team identity" and "aggression of football spectators" which was validated by It was approved by professors and researchers, and its reliability was also confirmed by calculating factor loadings, Cronbach's alpha coefficients, and composite reliability. After extracting and categorizing the collected information in the data analysis section, inferential and descriptive statistics were used. Also, the "variance-based structural equations" method was used to check the assumptions of the model. The current research included two hypotheses that after calculating the critical values and significance levels of the variables, both hypotheses were confirmed. The findings indicated that team identity has an effect on the tendency of football spectators to be physically aggressive. In fact, it can be said that as the audience's team identity scores increase, the audience's tendency to both types of aggression (physical and verbal) decreases and vice versa. Therefore, according to the results of the research, managers of football teams and officials of stadiums can adopt measures and plans to raise the level of team identity and increase the commitment and attachment of fans in order to create a safe and stable environment in stadiums.