This research aimed to examine the effects of process-based writing modular program on writer identity. Process based writing modular program has been developed by considering process-based writing approach. In this study, quasi-experimental design with a pretest-posttest was used. The research was carried out with six second grade students. The data was collected through semi-structured interview questions and content analysis method was used in the analysis of the data. The results showed that process-based writing modular program supported the students to think more about the writing subject. In addition, it was found out that the students were more positive about the editing and sharing of the writings they wrote. After the program, it was seen that the students gained sensitivity not only in terms of content but also in terms of formatting. In this process, it was determined that students diversified their writing content and subjects and became willing to write in different text types. In addition, it was found in the post-interview that the discourse about the importance of writing to the students increased.