The purpose of this study was to examine the effects of inferential reading strategy program on text comprehension and Korean language academic achievements of vocational high school students. We developed the program of inferential reading strategy, applied it to an educational spot, and examined the effects of it on text comprehension ability and Korean language academic achievements of learners. ANCOVA was used for data analysis with SPSS ver.12.0 statistic program. The main findings of this study were as follows. First, the experimental group which had been conducted with the inferential reading strategy program showed statistically significant difference in their text comprehension ability from controlled group. Second, the experimental group showed statistically significant difference in their Korean language academic achievements ability from controlled group. The study shows that the inferential reading strategy program had effect on the text comprehension and Korean language academic achievements of vocational high school students.