The goals of the present study were to (a) develop and validate a new self-report measure of social avoidance for use among early adolescents in mainland China and (b) explore the links between subtypes of social withdrawal (i.e., shyness, unsociability, and social avoidance) and indices of socio-emotional difficulties in this cultural context. Participants were 663 early adolescents (350 boys, 313 girls) attending elementary schools (X-bar[subscript age] = 10.25 years) and middle schools (X-bar[subscript age] = 12.53 years) in Shanghai, People's Republic of China. Measures of social withdrawal subtypes and adjustment were collected using multi-source assessments, including self-reports, peer nominations, and teacher ratings. The results provided evidence in support of the reliability and validity of the new scale of self-reported social avoidance. Shyness, unsociability, and social avoidance were also all uniquely associated with emotion dysregulation and self-reported internalizing problems. However, only social avoidance was uniquely associated with teacher-rated emotion symptoms and peer problems (as rated by both peers and teachers). Results are discussed in terms of the reasons why social avoidance may have particularly negative implications for early adolescents in China.