Abstract: OBJECTIVE To review researches on the association between NUDT 15 polymorphism and tolerance of thiopurine, thiopurine-induced leukopenia, hoping which can provide some help for its better clinical application. METHODS Searched domestic and foreign related literature, organized and comprehensive analyzed. RESULTS The people studied were mainly Asian, especially Korean and Japanese. However, there was only two studies in child acute lymphoblastic leukemia and 3 studies in inflammatory bowel disease in China. Most studies revealed that NUDT 15 c.415 C>T mutation was strongly associated with intolerance of thiopurines and thiopurine-induced leukopenia especially in Asians. Besides, several studies in inflammatory bowel disease also found that patients with c.415 C>T homozygous mutation were easier to develop severe hair loss. CONCLUSION Most studies have revealed that NUDT 15 c.415 C>T mutation is strongly associated with intolerance of thiopurines and thiopurine-induced leukopenia especially in Asians. Genotyping c.415 C>T genotype might provide help for a better clinical reaction. Whereas, researches on NUDT 15 other variants is few and need to explore further their.