Researchers have suggested the separation of the competency and affect components of academic self-concept but have not investigated the domain specificity and their differential impacts on the development of self-esteem. A sample of 7th grade students in China (N = 580) responded to survey items examining their self-concepts of competency and affect in Chinese, maths and general schoolwork and their self-esteem. Confirmatory factor analysis supported the distinct components in each of the subject domains. Path models supported Marsh's (1986) internal/external frame of reference model such that the paths from Chinese and maths achievement scores to Chinese and maths competency and affect constructs were positive only for corresponding domains. The paths from Chinese and maths components to general school self-concept were component specific such that competency had positive impacts only on the competency component whereas affect had impacts only on the affect component. Finally, the impact of general school competency was more pronounced than that of affect on students' self-esteem. The results provided strong support for the distinctiveness of the competency and affect components of academic self-concept.