Abstract The purpose of this study was to explore the effects of Bloom's mastery learning upon the achievement and selfconcept in mathematics of elementary school children. The major findings of this study are as follows: 1. In the mathematics instructions: the proportions of the three groups of students who answered the questions 2, 3, 6, 8, 10, attained to significant difference, while in the questions 1, 4, 5, 7, 9, there were no significant difference. 2. In the cognitive domain: (1) the mathematics achievement of post-test scores of the three groups were no significant differences; (2) the comparison between pretest and post-test, the variation of mathematics achievement of the three groups decreased significantly; (3) the mathematics operational measurement of post-test scores of the three groups did not change significantly; (4) the comparison between pre-test and post-test, the variation of mathematics operational measurement in the E1, E2 group and the control group tended to decrease significantly. 3. In the affective domain: (1) the three groups in the post-test scores of mathematics self-concept showed no significant differences; (2) the comparison between pretest and post-test, the mathematics self-concept of the E1 and E2 group was significantly positive; while the E2 and control group showee no significant difference.