This study examined the mediating effect of mental health problems on correlation between self-concept and school adjustment of adolescents, and test the differences of latent means and path coefficients between low achieving students and students without disabilities. The data of 1,126 low achieving students and 5,407 students without learning disabilities were chosen from the fourth year survey of ‘Korean Educational Longitudinal Study(KELS) 2013’, and SEM analysis, bootstrapping, latent mean analysis, and multi-group path analysis were conducted. As a result, it was confirmed that self-concept had a positive effect on school adjustment, and mental health problems also had a mediating effect on the correlation between self-concept and school adjustment. Comparison between a low achieving group and a group without disabilities indicated that low achieving students showed a higher level of mental health problems and lower levels of self-concept and school adjustment than students without disabilities. In addition, the path coefficient from self-concept to school adjustment in a low achieving group was lower, while the path coefficient from self-concept to mental health problems in a low achieving group was higher, compared with path coefficients observed in a group without disabilities. From the results above, discussions of the current study and suggestions for the further study were described.