【Objective】To investigate the effect of CYP3A5 and MDR1 polymorphism in the donor/recipient on the concentration /dose ratio of Tacrolimus in Chinese liver transplant patients. 【Methods】Blood samples were collected from liver transplant patients who received Tacrolimus in the third affiliated hospital of Sun Yat-sen university

and the tissue samples were collected from the corresponding donors. The CYP3A5 andMDR1 genotypes were determined by PCR-RFLP method. At 1

2

4 and 12 weeks after transplantation

Tacrolimus doses(mg/kg/day) and trough blood levels(C0) were determined. 【Results】The concentration /dose ratios of patients with CYP3A5*1 /*1 and CYP3A5 *1/*3 donors were significantly lower than those with CYP3A5*3/*3 patients at 2

4 and 12 weeks after liver transplantation. No difference was found among the MDR1 genotypes in donor /recipients or CYP3A5 genotypes in recipients. The same results were found in the analysis of the combination of both dornors and recipients. 【Conclusion】CYP3A5 *1/* 3 polymorphism in the donor is correlated with the whole blood concentration /dose ratio in Chinese liver transplant patients. Donors with CYP3A5 *1 allele require more tacrolimus to reach target concentrations compared to those with CYP3A5 *3/* 3 genotype.