The purpose of the present study is to investigate affective variables comprehensively and to analyze the effect of selected affective variables on academic achievement. For this purpose the following questions are examined: First, is there any significant correlation among selected affective variables? Second, is there any significant correlation between affective variables and academic achievement? Third, which variable among 7 affective variables perdicts academic achievement best? Fourth, does the correlation between affective variables and academic achievement become increased as the learning hierarchy of subjuct-matter becomes clear? The persent study deals with 7 affective variables: learning motivation, learning attitude, level of aspiration. ingernal-external locus of control, test anxiety, acadmic self-concept, and mental health. The major findings of the present study are summarized as follows: First, there is generally significant correlation among selected affective variables. Second, there is generally significant correlation between affective variables and academic achievement. Third, level of aspiration among 7 affective variables predicts academic achievement best. Fourth, the correlation between affective variables and academic achievement becomes increased as the learning hierarchy of subject-matter becomes clear. In conclusion, affective variables are found to be closely related with acdemic achievement, and to improve academic achievement, the improtance of affective domain as well as cognitive one in education should be emphasized.