OBJECTIVE: To investigate the association of synergistic effects of Wuzhi capsules on tacrolimus with CYP3A5*3 (6986A>G,rs776746) gene polymorphisms. METHODS: One hundred and severty patients underwent renal transplantation receiving tacrolimus maintenance therapy after surgery were selected from our hospital during Jan. 1997-Dec. 2015, and then divided into Wuzhi capsules (+)group (74 cases) and Wuzhi capsules(-)group (96 cases) according to the use of Wuzhi capsules. Both groups received tacrolimus+mycophenolate mofetil+prednisone; Wuzhi capsules (+)group was additionally given Wuzhi capsules, one capsule each time, bid, for more than 12 months. Trough concentration of tacrolimus was detected by CMIA 0, 1, 3, 6, 12 months after medication, and the blood concentrations (C0/D) were calculated at different time points after correcting daily dose. CYP3A5*3 gene polymorphisms was detected by PCR-RFLP. The association of C0/D value with gene polymorphism was investigated by analysis of covariance. RESULTS: Among 170 patients, there were 65 cases of CYP3A5 GG genotype, 83 cases of AG genotype and 22 cases of AA genotype; genotype frequencies were 38.2%, 48.8% and 12.9%, which was in line with Hardy-Weinberg balance (P>0.05). There was statistical significance in the distribution frequencies of GG, AG+AA genotype between Wuzhi capsules (+) group and Wuzhi capsules(-)group (P<0.05). After 1 month of medication, C0/D of tacrolimus in GG genotype was significantly higher in Wuzhi capsules (+)group than in Wuzhi capsules(-)group. After 1, 3, 6, 12 months of medication, C0/D of tacrolimus in AG+AA genotype was significantly higher in Wuzhi capsules (+) group than in Wuzhi capsules(-) group, with statistical significance (P<0.05). There was no statistical significance in C0/D of tacrolimus in GG genotype between 2 groups after 3, 6, 12 months of treatment (P>0.05). CONCLUSIONS: Wuzhi capsules can increase C0/D of tacrolimus in CYP3A5*3 AG+AA genotype, but have no significant effect on C0/D of tacrolimus in GG genotype; CYP3A5*3 genotype should be considered when using Wuzhi capsules as synergist of tacrolimus.