Adolescent mental health has become a public concern, and it is necessary to know how problem behaviors affect academic achievement. The current study surveyed 12,672 adolescents in eastern China, and results indicated clinical cut-offs on each problem behavior. We then examined how internalizing problems lead to negative academic results. Findings suggest Attention problems are a key factor. Anxiety/ depression and somatic complaints have no direct effect on academic performance but are mediated by attention problems. This study can serve practice of schooling and parenting, and provide basis for developing clinical intervention strategy in China.eey oodd: K internalizing problem, adolescent, academic achievement, attention problem, mediating effect