An integrated approach on concept diagnosis is investigated in this study. Polytomous item relational structure (PIRS) is developed so that it is beyond the limitation of dichotomous items. Besides, student problem chart (S-P chart) is used to classify examinee into proper learning style. The integrated methodology of PIRS and S-P chart could display features of concept structures for each learning style. Features of concept structures for each learning style will demonstrate information of concept diagnosis. An empirical testing data of fraction subtraction for pupils is analyzed. Results show this integrated methodology will be useful for remedial instruction.