This six-wave longitudinal study in Project P.A.T.H.S. examined the growth trajectories and predictors of moral competence in Chinese adolescents in Hong Kong. Linear mixed models utilizing individual growth curves were used to analyze the initial status and rate of change of moral competence with reference to gender, economic disadvantage, family intactness, family functioning and parent-child subsystem quality. Results showed that adolescent moral competence increased across 6 years. Female adolescents had higher initial levels of moral competence than that of male adolescents. Adolescents from well-functioning families had higher initial levels of moral competence but slower growth of moral competence than did those from families with lower family functioning. Adolescents with higher mother-child subsystem quality had higher initial levels of moral competence but slower growth of moral competence than did those with relatively lower mother-child subsystem quality. Finally, adolescents with higher father-child subsystem quality had higher initial levels of moral competence than those with relatively lower father-child subsystem quality.