Objective To investigate the correlation between CYP3 A4 gene polymorphism and individual differences in the therapeutic effect of Tripterygium wilfordii on rheumatoid arthritis（RA）.Methods 58 RA patients taking tripterygium glycosides tablets orally were selected and CYP3 A4 single nucleotide polymorphism（SNP） were detected by SnaPshotmethod.Hardy-Weinberg equilibrium verification and correlation test were performed using Pearson Chi-Square test.The relationship between CYP3 A4 genotype and the therapeutic effect of tripterygium wilfordii in patients with rheumatoid arthritis was analyzed by binary Logistic regression model to see the individual differences between CYP3 A4 gene polymorphism and the therapeutic effect of Tripterygium wilfordii on rheumatoid arthritis.Results Genotype to Hardy-Weinberg genetic balance was reached in 58 patients with（P>0.05）,the three genotypes（GG,GA,AA） efficient difference was statistically significant; when comparing in pair, there was no statistically significant difference in the effective rate between GG and AA type（P>0.05）,and but was statistically significant difference between GA and AA type efficient difference（P<0.05）.Conclusion The individual difference in therapeutic effect of tripterygium wilfordii in patients with rheumatoid arthritis was related to SNP polymorphism of CYP3 A4 gene.It was most effective to in AA type of patient taking Tripterygium wilfordii,then less in GA type, and lest in GG type.