--- - |2 Abstract This study aims to examine how family social capital mediates the relationship between poverty and children's anxiety and depression in mainland China. Data were collected with multistage cluster random sampling method in Xiushui City in mainland China. The sample comprised 1,314 school‐aged children (Grades 4–9). Data included children's basic demographics, internalizing symptoms, and parenting process. Structural equation modeling was used to test the hypothesized model. The results demonstrated a good fit for the sample. The overall model explained 12.7% and 16.1% of the variance for children's anxiety and depression, respectively. Poverty had a significantly direct effect on children's anxiety and depression, and family social capital could partially mediate the influence of poverty on children's internalizing symptoms. Family social capital plays an important mediating role between poverty and children's mental health. Our findings provide strong evidence for social work intervention. Family social capital is essential for parent–child interactions, especially in underprivileged families. - Journal of Community Psychology, Volume 46, Issue 8, Page 983-995, November 2018.