This study investigates how writing tasks in 10th-grade English textbooks in South Korea have evolved across six national curricula, from the 5th to the 2022 Revised Curriculum, excluding the 2009 Revised Curriculum, which did not mandate the use of textbooks for this grade level. The study examined writing tasks from 16 textbooks, analyzing their instructional focus, the integration of pre-, while-, and post-writing components, degree of collaboration, and genre distribution. The findings indicate a gradual shift from sentence-level, language-focused tasks to paragraph-level, meaningmaking tasks. Process-oriented elements, particularly pre- and post-writing components, have become more common, though post-writing activities remain limited to peer review. The provision of paragraph skeletons has increased over time. Peer-based collaboration has increased, but group writing tasks have nearly disappeared. Genre coverage has broadened over time, yet expository writing continues to dominate. This study underscores the importance of continued attention to how writing is represented in instructional materials to support more pedagogically informed L2 writing instruction.