Objective To systematically evaluate the association of NUDT15 gene polymorphism with thiopurine-induced leukopenia.Methods Relevant articles were searched electronically from CNKI,WanFang Data,VIP,CBM,PubMed and Embase from inception of the databases to June 2023.The quality of the included articles was evaluated using the Newcastle-Ottawa Quality Assessment Scale(NOS),a Meta-analysis was conducted by Stata 14.0 software.Results Seventeen articles involving 4 057 patients were included.Among them,1 017 patients developed leukopenia or neutropenia in varying degrees after using thiopurine drugs.Results of Meta-analysis showed that the overall effects of each group were statistically significant(P<0.001)under the NUDT15 gene polymorphism:for the leukopenia caused by medication within 8 weeks,the allele model[OR= 0.15,95%CI(0.10,0.22),P<0.001],the dominant gene model[OR = 0.13,95%CI(0.08,0.20),P<0.001],and the heterozygous gene model[OR = 0.04,95%CI(0.01,0.19),P<0.001]were statistically associated with leukopenia;for the leukopenia after 8 weeks,the allele model[OR= 0.18,95%CI(0.11,0.30),P<0.001],the dominant gene model[OR = 0.17,95%CI(0.09,0.31),P<0.001],the heterozygous gene model[OR = 0.05,95%CI(0.02,0.15),P<0.001]were statistically associated with leukopenia;for the grade 3 to 4 severe leukopenia,the dominant gene model[OR=0.09,95%CI(0.05,0.15),P<0.001]was statistically associated with leukopenia.Conclusion The polymorphism of NUDT15 gene was associated with leukopenia induced by thiopurines.