ABSTRACT The purpose of this study was to explore the effects of Bloom's mastery learning upon the achievement and self-concept in mathematics of elementary school children. The major findings of this study are as follows: 1) In the survey of the mathematics instructions: the proportions of the three groups of students who answered the questions 4, showed significant difference,while in the rest of the questions, there was no significant difference. 2) In the cognitive domain: (1) the mathematics achievement of post-test scores of the three groups had no significant difference; (2) according to the comparison between pre-test and post-test, the variation of mathematics achievement of the three groups all increased. 3) In the affective domain: (1) it showed no significant difference in the three groups, post-test scores of mathematics self-concept; (2) the comparison between pre-test and post-test, indicated the variation of mathematics self-concept of the three groups showed no significant difference.