Justice has become the main theme of the community. In the field of psychology, Piaget is the earliest to study fair of justice as a moral standard, based on the two aspects of behavior and judgement the fairness of individual distribution.The present research explored the children’s justice of distribution of rewarding and punishing in the situation of social exclusion and social acceptance. With the individual-accidental exclusion paradigm and the third-party reward and penalty allocation paradigm, the behavior of the justice of reward and punishments, as well as the judgment of the justice of reward and punishments were studied among 8-9-year-old children. In study 1, the aim of the experiment was to analyse the characteristic of, as well as the effect role of social exclusion in the behavior of distributive justice about the distribution of rewarding and punishing among children aged 8-9. A 2(social situation:social exclusion vs.social acceptance)×2(8-year-old vs. 9-year-old)×4(type of behavior task:good behavior awarded vs. bad behavior punished vs.good behavior punished vs. bad behavior awarded) mixed design was adopted in study 1. A total of 122 children aged 8-9 aged were tested and were randomly assigned to the experiment group.The results were as follows: (1)The fair behavior of rewards and punishments in the social exclusion group was significantly more than that in the social acceptance group, and the unfair behavior of reward and punishments allocation in the social exclusion group was significantly less than that in the social acceptance group;(2)In the social exclusion group, the fairness of reward and punishments was higher than that of the social acceptance group. In study 2, the intent of the experiment was to analyse the characteristic of, as well as the effect role of social exclusion in the judgement of distributive justice about the distribution of rewarding and punishing among children aged 8-9. A 2(social situation:social exclusion vs.social acceptance)×2(8-year-old vs. 9-year-old)×4(type of judgement task:targeted punishment vs. targeted reward vs. collective punishment vs. collective reward) mixed design was adopted in study 2. A total of 126 children aged 8-9 aged were tested and were randomly assigned to the experiment group.Results showed that (1)The judgement of the reward and punishments distributive justice in the 9 year-old group was significantly higher than that of the 8-year-old group, and the unfair behavior of reward and punishments of the 9-year-old group was lower than that of the 8-year-old group; (2) The fair judgment of reward and punishments allocation of the 9-year-old group was significantly higher than that of the 8-year-old group, and the unfair distribution of reward and punishments of the 9-year-old group was lower than that of the 8-year-old group. In conclusion, the present study demonstrated in the context of social exclusion, there were significantly improving trend with age increasing in the fairness, including the behavior of children's reward and punishment distribution, as well as the judgment of children's reward and punishment.