This study aims to describe achievement motivation on outstanding students in learning to write at the fifth grade primary schools students. The research method used is descriptive qualitative. Subjects in this study were 18 achieving students. The data were collected through questionnaire, interview and observation. Analytical techniques used are interactive analysis consisting of data collection, data reduction, data presentation and conclusion. The results of this study indicate that the achievement motivation on outstanding students in learning writing is good, this happens because of several factors that support outstanding students in learning writing have good achievement motivation. There are factors of individuals (intern) and environmental factors (external), an individual factor which consists of (1) the competence of students; (2) belief to succeed, while environmental factors consists of (1) the competitive situation; (2) support from parents; and (3) schools, including how to teach teachers.