Pro-group behavior is of great value for the survival and development of individuals and groups during the evolution and interaction between individuals and groups．Because of the group’s functionality to individual fitness, people show a great motivation to seek social connections and engage in pro-group behavior tendencies. However, social exclusion thwarts this connection between individuals and groups. According to the results of previous studies, people may either withdraw or engage in pro-group behavior tendencies to response for being excluded by their groups. According to the regulatory focus effect of power, high power individuals with promotion focus tend to display approach-oriented behaviors; low power individuals who taking prevention focus are more likely to perform avoidance-oriented behaviors. The two behavioral tendencies align with the aforementioned reactions to social exclusion. It can be seen that individual differences in the level of power are a non-negligible factor affecting individual pro-group behavior tendencies. Therefore, this study explores the moderating effect of a sense of power on the relationship between social exclusion and pro-group behavior tendencies. Study 1 used the social exclusion scale and pro-group behavior tendencies scale to explore the relationship between social exclusion perception and pro-group behavior tendencies. A total of 240 participants working in full-time positions completed this survey via the Internet platform. Study 2 was conducted in the laboratory with 121 college students. It was a 2 (condition: exclusion vs. inclusion) × 2 (power: high vs. low) between-subjects design. The sense of power was manipulated by writing about a personal incident in which they were powerful or powerless. After completing the power prime, participants were randomly assigned to exclusion condition or inclusion condition by the group exclusion paradigm. We conducted study 3 to further examine the moderating role of trait power in the relationship between social exclusion and pro-group behavior tendencies. Study 3 with 64 college students was same to the study 2 except that the trait power of participants was measured by the Sense of Power Scale instead of power prime. Participants firstly completed the Sense of Power Scale. Then, they were randomly received exclusion or inclusion feedback by using the group exclusion paradigm. After that, all the subjects responded to the pro-group behavior tendencies measurement. Based on the above studies, we got the following results :(1) there is a significant positive correlation between social exclusion perception and pro-group behavior tendencies;(2) the trait power and the personal power by manipulated in laboratory situation both has a significant moderated the relationship between the social exclusion and pro-group behavior tendencies;(3) the participants with high power exhibited more pro-group behavior tendencies when suffered from social exclusion than those with low power. For the participants who are included by group, the level of power has no effect on pro-group behavior tendencies. We conclude that the sense of power was identified as a moderator of the effects of social exclusion on pro-group behavior tendencies and further help illuminate the mechanisms underlying the effects of social exclusion.