ALM In order to study the association between the null genotypes of GSTM1 and GSTT1 and the genetic susceptibility to hepatocellular carcinoma (HCC).METHODS The genotypes of GSTM1 and GSTT1 of 63 cases of HCC and 88 controls were detected with the multiple PCR technique.RESULTS The frequency of GSTM1 null genotype was 57.1% among the cases, and 42.0% among the controls, the difference being statistically significant (x2 = 3.35, P = 0.067),but X2 value approaching the significance level.The odds ratio was 1.84 (95% Cl=0.91 - 3.37).The frequency of GSTT1 non-null genotype was 87.3% among the cases and 62.5% among the controls, the difference being statistically significant (X2=11.42, P=0.0007274). The odds ratio was 4.13 (95% Cl = 1.64 - 10.70).According to the cross analysis, the GSTT1 nonnull genotype was more closely associated with HCC than GSTM1 null genotype, and these two factors play an approximate addlitive interaction in the occurrence of HCC.CONCLUSION The persons with GSTM1 nullgenotype and GSTT1 non-null genotype have the increased risk to HCC.