The purposes of this study were to the learning effects of CAI and traditional instruction methods in the Home Economics class of middle school and to examine the difference of learning effect between CAI group and traditional instruction group according to ability level. The research findings are as follows ; 1. ① As a result of the post test, CAI group showed significantly higher scores on academic achievement than those of traditional instruction group(p<.05) ② As a result of the retention test, CAI group showed higher scores than those of traditional instruction group, but statistically the difference is not so significant 2. ① Higher group in pre-test score of CAI group showed higher scores in post-test and rerention test than those of traditional instruction group, but statistically the difference is not so significant. ② Lower group in pre-test score of CAI group showed significantly higher academic achievements than those of traditional instruction group(p<.05) ③ Higher group in IQ test score of CAI group did not show significantly higher academic achievements that those of traditional instruction group. ④ Lower group in IQ test score of CAI group showed significantly higher academic achievements than those of traditional instruction group(p<.05).