Employing the quasi-experimental design using pre-test and post-test on random subjects, the present study was aimed at analyzing the effectiveness of learning methods applied in theteaching of chemistry for the tenth graders of State University of Malang Laboratory School. The experiment groups learned chemistry using the inquiry methods and the control one using the conventional method (lecture-lab work). The study found that there were significant differences of achievement among the groups β the anova test results in Fcount (11.995) > Ftable (3.115). Furthermore,the effectiveness of learning methods can be seen from the average achievement in cognitive,psychomotor, and affective assessments. Guided inquiry learning method was effective in increasing students\u27 learning achievement. This can be seen from their results of cognitive, psychomotor, and affective assessments, which were 72.16, 79.69, and 80.58 respectively. Open inquiry was also effective in increasing students\u27 achievement; their average results of cognitive, psychomotor, and affective assessments were 63.39, 80.25, and 81.43 respectively. Unlike the previous two methods, the conventional method gained less; students\u27 average results of cognitive, psychomotor, and affective assessments were 54.14, 70.42, and 78.65 respectively