自尊是自我的重要组成部分，是在社会比较和他人评价中形成的对自我价值的情感体验，对儿童个体行为和心理健康等方面产生深远影响。研究表明，自尊水平发展是毕生的，且表现出特定的发展特征，在中小学时期容易产生自尊波动。同时，随着儿童升入初中，与父母、老师等成人的关系从依赖走向自主，更加平等的同伴关系成为儿童重要支持来源。但在以往研究中，关于同伴关系、自尊和年级三者间作用机制的研究较少。本研究聚焦于自尊和同伴关系均发生剧烈变化的4-9年级，同时探讨年级在同伴关系和自尊之间的作用机制。

本研究以河南、陕西省共4013名中小学学生为研究对象，采用问卷调查法，分别考察了研究对象的同伴关系、亲子关系、师生关系、自尊水平等现状，探索了同伴关系与自尊之间的关系，分析了年级在儿童同伴关系和自尊中的调节作用。研究的主要发现如下：

第一，儿童自尊水平和同伴关系在年级、家庭经济状况以及父母受教育程度上均存在显著差异。

第二，不同年级同伴关系各维度对儿童自尊均具有显著影响。具体表现为儿童同伴鼓励陪伴与支持程度越高，其自尊水平越高；同伴冲突与惩罚程度越高，其自尊水平越低；同伴关系满意度越高，其自尊水平越高。

第三，在控制亲子关系和师生关系各维度影响后，7-9年级儿童同伴关系中鼓励陪伴与支持维度和冲突与惩罚维度与自尊的相关程度高于4-6年级儿童。

第四，年级在同伴关系与儿童自尊之间起到调节作用。相比于4-6年级儿童，7-9年级儿童的同伴鼓励陪伴与支持维度对自尊的正向预测作用更强，同伴冲突与惩罚维度对自尊的负向预测作用更强。

根据研究结果，本研究从社会工作的视角出发，针对不同年级儿童同伴关系和自尊发展特点，结合优势视角、社会支持、社会学习等理论，提出社会工作专业干预建议，为儿童营造良好的同伴交往氛围，促进儿童自尊的稳定发展。

Self-esteem is an important part of Ego. It is an emotional experience of self-worth formed in social comparison and evaluation of others. It has a profound impact on children's individual behavior and mental health. Studies have shown that self-esteem levels develop throughout life and exhibit specific age characteristics. It is easy to produce self-esteem fluctuation during primary and secondary school. At the same time, as children enter junior high school, their relationship with parents, teachers and other adults changes from dependence to autonomy, and more equal peer relationship becomes an important source of support for children. However, there are few studies on the mechanism of peer relationship, self-esteem and grade. This study focused on grades 4-9 where both self-esteem and peer relationship have undergone drastic changes, and explored the mechanism of peer relationship and self-esteem among grades.

In this study, a questionnaire survey was conducted among 4013 primary and secondary school students in Henan and Shaanxi. We investigated the status of the study subjects' peer relationship, parent-child relationship, teacher-student relationship and self-esteem. We explored the relationship between peer relationship and self-esteem, and we also analyzed the moderating role of grades in children's peer relationship and self-esteem. The main findings are as follows:

First, children's self-esteem and peer relationship have significant differences in grades, family economic status and parents' educational level.

Second, each dimension of peer relationship in different grades has significant influence on children's self-esteem. The specific results are as follows: The higher level of encouragement, companionship and support from children's peers, the higher their self-esteem. The higher level of peer conflict and punishment, the lower their self-esteem. The higher peer relationship satisfaction, the higher their self-esteem.

Thirdly, after controlling the influence of all dimensions of parent-child relationship and teacher-student relationship, the dimensions of peer encouragement, companionship and support were more correlated with self-esteem in grade 7-9 than in grade 4-6, as were the dimensions of peer conflict and punishment.

Fourth, grades play a moderating role between children's peer relationship and   self-esteem. Compared with children in grade 4-6, children in grade 7-9 had more positive predictors of self-esteem from the dimension of peer encouragement, companionship and support, and more negative predictors from the dimension of peer conflict and punishment.

According to the research results and the characteristics of peer relationship and self-esteem development of children in different grades, this study proposes professional intervention suggestions, which combining with Strength Perspective, Social Support, Social Learning and other theories from the perspective of social work. This study is devoted to creating a good environment for children's peer communication and promoting the stable development of children's self-esteem.