This study evaluates a model linking shyness, aspects of peer relations, and internalizing problems among young adolescents in the People's Republic of China. Participants were 547 young adolescents from Shanghai, China (46% boys; M  = 10.35 years, SD = 0.77 years) who completed peer nominations of shyness, rejection, and victimization, and self-report measures of loneliness, depression, and friendship support. Analyses demonstrated that peer difficulties (rejection, victimization) mediated the associations between shyness and internalizing problems. However, moderated mediation analyses revealed a protective effect for highly supportive friendships, especially for boys. Findings highlight the importance of considering different types of peer experiences in studies of shy young adolescents and are discussed in terms of importance to theory and intervention in China and elsewhere.