The main purpose of this study is to examine effects of teaching/learning methods of mathematics utilizing to writing and corrective feedback on academic achievement and sense of self-efficacy in mathematics. The research questions are: What is the difference in the academic achievement and sense of self-efficacy in Mathematics between experimental group and the controlled group? And what is the difference in the academic achievement and sense of self-efficacy in Mathematics between teacher's corrective feedback group and no feedback group? To test the above topics of interest, the study selected 98 sixth grade students from Jeonju, Yelementary school as participants in the study. Then they were divided three sub-groups designated as an experimental group Ⅰ in an experimental group, an experimental group Ⅱ in an experimental group and a controlled group. Data were analyzed through one-way ANCOVA. The results showed that, first of all, there was a significant difference between experimental group and the controlled group in their effect on academic achievement. The second, there was a significant difference between experimental group and the controlled group in their effect on the students' sense of self-efficacy. The third, there was a significant difference between mathematics in teacher's corrective feedback group and no feedback group after mathematical writing activities on academic achievement. The fourth, there was a significant difference between mathematics in teacher's corrective feedback group and no feedback group after mathematical writing activities on the students' sense of self-efficacy. On the basis of this study, the educational implication is drawn that teaching/learning methods of mathematics utilizing to writing has more positive effects than traditional instruction to improve the students' academic achievement and sense of self-efficacy in mathematics. After mathematical writing, teacher's corrective feedback has more positive effects than no feedback to improve the students' academic achievement and sense of self-efficacy in mathematics.