To investigate the effect of empathy on depressive symptoms in adolescents and to explore the potential mediating role of family functioning in the effect of empathy on depressive symptoms. The 2022 cross-sectional data from the Chengdu Positive Child Development (CPCD) cohort were analyzed in the study. A survey was conducted in Chengdu in June 2022, involving 3020 students in grades 5-8 from three randomly selected stratified schools. The Interpersonal Reactivity Index (IRI-C), the Chinese Family Assessment Instrument (C-FAI), and the Center for Epidemiologic Studies Depression Scale for Children (CES-DC) were used in the survey. Chi-square test or one-way analysis of variance was performed to examine the differences in various demographic characteristics (sex, grade, region, and total monthly household income) between groups of respondents, as well as the differences in family functioning, empathy, and depression. Pearson correlation coefficient was used to examine the correlation between family functioning, empathy, and depressive symptoms. Structural equation modeling and SPSS PROCESS component Model 4 were used to analyze whether family functioning played a mediating role in the effect of empathy on depressive symptoms in adolescents. The detection rate of depressive symptoms among survey respondents was 25.40%. The results of the difference analysis revealed significant differences in the detection rates of depressive symptoms among respondents of different grades, regions, and monthly household incomes (P<0.05). There was no significant difference in the detection rates of depressive symptoms between male and female students. There was a significant difference in the detection rate of depressive symptoms between respondents with different scores for family dysfunction and empathy ability (P<0.001). Correlation analysis results showed that empathy scores were negatively correlated with depression (r=-0.11, P<0.001), that family dysfunction was positively correlated with depression (r=0.29, P<0.001), and that empathy scores were negatively correlated with family functioning (r=-0.37, P<0.001). The mediating role of family dysfunction in the relationship between empathy and depressive symptoms was established, with the direct effect being 0.039 (95% confidence interval [CI]: 0.010-0.069, P<0.001) and the indirect effect value being -0.096 (95% CI: -0.115--0.079, P<0.001). The direct effect value accounted for 28.89% of the total effect value, while the mediation effect value accounted for 71.11% of the total effect value. The empathy ability of adolescents is correlated to depressive symptoms, and family functioning plays a mediating role between empathy and depressive symptoms in adolescents. It is suggested that adolescents' empathy ability and family functioning should be enhanced through multiple channels to reduce the occurrence of depressive symptoms.