The National Longitudinal Cohort of Hematological Diseases in China (NICHE) project was initiated in 2019 to create China's first prospective longitudinal national multi-disease cohort of patients with blood diseases. Over the past five years, the NICHE project has established special disease cohorts for 13 hematological diseases, maintaining a forward-looking characteristic while combining with existing large-scale special disease databases to conduct cohorts with two-way research characteristics. With the active support of clinical experts, real-world data-based research has yielded results in the fields of hemophilia, leukemia, lymphoma, myeloma, regenerative medicine, and transplantation. We hope that the NICHE platform will continue to foster discussions among researchers in the fields of hematology and stem cell research, leading to the establishment of meaningful collaborations among international investigators.