Self-concept is an important domain in psychology.Academic self-concept is a vital part of selfconcept.In this paper,the relations between academic self-concept and academic achievement for junior middle school students were examined by the scale developed by the authors.The results show;1)There is a significant different correlation between academic self-concept and academic achievement;2)A significant grade effect was found in academic self-concept.3)A significant difference in academic self-concept was found between groups of different academic achievements.