Abstract： Objective To study the association between the polymorphism of N-acetyltransterase 2(NAT2) gene and antituberculosis drug-induced liver injury (ATLI).Methods In this case-control study,the NAT2 genotypes of 119 pulmonary tuberculosis patients with ATLI and 198 patients without ATLI were analyzed by PCR sequencing technique.The association between NAT2 polymorphism and ATLI was examined by SAS9.13 software.Results The NAT2 was divided into three types according to metabolism rate of their gene phenotype: rapid type (4/4),intermediate type (4/5A,4/5B,4/5C,4/6,4/7) and slow type (5B/6,5B/7,6/6,6/7,7/7).There was a significant statistical difference in genotype frequency between the two groups of patients (P＜0.05).Logistics regression analysis demonstrated that the ATLI risk individuals with slow-type NAT2 was 1.91 times of intermediate- and rapid-type patients combined (OR,1.91 ; 95％ CI,1.10-3.33).Further,stratification analysis showed that slow-type subjects aged older than 40with negative sputum smear were more likely to have liver injury (P＜0.05).Conclusion ATLI is associated with NAT2 genotype,and therefore NAT2 genotyping before antituberculotic medication is recommended for guiding clinical practices.