The present study explored the development of writing performance and discourse organization in Chinese as a second language (L2) writing, focusing on the effects of genre and learning context. Tracking an L2 Chinese learner’s written production in two genres (i.e., narrative and argumentative) across four learning contexts (i.e., pre-study abroad, study abroad, post-study abroad, and delayed post-study abroad) longitudinally over four years, this study revealed that holistic ratings and discourse organizational devices showed distinct patterns in different genres and across learning contexts. Narrative essays generally received lower ratings than argumentative essays. Ratings of narrative essays remained relatively stable across four learning contexts, whereas those of argumentative essays displayed an omega-shaped pattern over the four-year period. Among six discourse organizational devices, subordinate clauses, textual connectives, and grammatical metaphors were used more in argumentative essays, but coordinate clauses and topic-prominent constructions were used more in narrative essays. The six discourse organizational devices exhibited discrete developmental trends throughout the four years of learning. This study provides a deeper understanding of writing performance and discourse organization in L2 Chinese development.