The purpose of this study were: (1) to find out the difference of students’ writing competence who studied with the method of Student Teams-Achievement Divisions (STAD), Inquiry Based Learning (IBL), and Expository; (2) to find out the difference of students’ the writing competence who have a high interest in reading and students who have a low interest in reading; and (3) to find out the interaction between learning method and the reading interest to writing competence. This research is a quasi experimental / quasi (quasi-experiment) with 3 X 2 factorial design. Population of this study is all elementary school students in Kebumen regency. The research samples of this study are SDN 3 Sawangan Alian, SDN 1 Kebulusan Pejagoan, and SDN 5 Bumirejo Kebumen, while the sampling technique used was multistage random sampling. Data collection techniques used in this study were task test which is to measure students’ writing competence and questionnaire to measure students’ interest in reading. Analysis of the data using analysis of variance two lines (ANOVA AXB). The results showed that the average competence of the group of students who are learning to write with STAD method is 75.69; group of students who learn writing with IBL method is 73.25; group of students who studied with Expository method is 71.64; the average competence of students group of low reading interest is 72.26; and the average competence of students group of high reading interest is 74.93. Conclusions of this study are: First, there is a difference between writing competence of students who study with STAD method, IBL, and Expository. Writing competence of students who study with STAD method is better than students who studied with IBL method and students who studied with IBL method is better than the students who studied with Expository method. Second, there is a difference between writing competence of students who have a low interest in reading and students who have a high interest in reading. Students who have a high interest in reading have a better writing competence than students who have a low reading interest. Third, there is no interaction between learning method and the reading interest to the writing competence.
