The purpose of this study is to investigate the educational effects of composing in music class for the fifth grade students in a elementary school. For the research, the researcher was constructed the teaching strategies for composition class, the specific tasks to develop the students` creativity, and portfolio as an evaluation tool. The subjects received music instruction from a classroom teacher for 45 minutes twice per week from March to December, 1997. All the class was videotaped for assessing and maintaining a record of both individual and class progress. Based on the results, what aspects of students and teacher changed was analyzed: 1) musical understanding, 2) performance ability, 3) reflective thinking, 4) music attitude, and 5) teacher`s reponses to composition class and portfolio.