Abstract
The opening of the two-child policy has resulted in more non-one-child families, which makes their family and social relations more and more complicated. As two different aspects of interpersonal relations within and outside the family, sibling relationship and peer relationship have their similarities but also have differences. Based on previous studies at home and abroad, this study briefly summarizes the characteristics, theoretic mechanism and influencing factors of sibling relationship and peer relationship. In addition, the association between sibling relationship and peer relationship is discussed, and the influence mechanism of the former on the establishment and development of the latter, as well as an integrative model of them, is developed. Last, it emphasized that future studies should focus on sibling bullying and sibling abuse, compare the peer relationship between only-child and non-only-child, strengthen the two-way mechanism of sibling relationship and peer relationship, and explore specific measures such as training prevention and intervention.