This research was motivated by the problem of writing personal letters at SDN Ujungberung V. Based on the results of observations in the field, it was found that many students were less able to write personal letters, were still difficult to express ideas in making personal letters, and did not pay attention to spelling in writing. The purpose of this study was to describe the process and ability of students in writing personal letters. For this reason, researchers used a genre-based writing model to improve the processes and abilities of students in writing personal letters. The research method used is a classroom action research method (PTK) using Elliot's design. In this study, researchers used instruments in the form of observation sheets, field notes, interviews, documentation, and tests. Data analysis was performed using quantitative, qualitative and triangulation techniques. Based on the findings in the field, there were several important problems related to writing personal letters. Students are not familiar with the structure of personal letters, written personal letters are not in accordance with a predetermined theme and pay less attention to spelling in writing. Judging from the results of the ability to write personal letters, each cycle has increased. This is evident from the average value of the ability to write personal letters obtained by students from each cycle. Cycle I: 68.26, Cycle II: 81.58, and Cycle III: 89.94. Thus the researcher recommends the teacher to use a genre-based writing model as a solution to improving students' personal letter writing skills.