Our study retrospectively analyzed 61 hematologic malignities with RAS mutation who underwent allo-HSCT at Beijing Gaobo Boren Hospital between January 2018 and January 2023. Twenty-five patients received maintenance therapy with trametinib post-HSCT(trametinib group), and 36 patients did not receive any maintenance therapy (control group)....the overall survival(OS) was 81.2% (95%CI: 68.6-89.1%). The disease-free survival (PFS) was 73.0% (95%CI: 59.7-82.5%). Trametinib group, the OS was 91.5% (95%CI: 70.0-97.8%), PFS was 88.0% (95%CI: 67.3-96.0%). Control group, the OS was 73.9% (95%CI: 55.9-85.6%), PFS was 65.8% (95%CI: 47.7-78.9%). Trametinib significantly improved the OS and DFS (P=0.044; P=0.041).