Abstract: OBJECTIVE To evaluate the pharmacoeconomics of clinical pharmacists participating in the individualized administration of tacrolimus in the treatment of idiopathic membranous nephropathy(IMN). METHODS Sixty patients diagnosed with IMN in Nanjing Drum Tower Hospital from January 2018 to June 2020 were included in the prospective study, they were randomly divided into clinical pharmacist intervention group(30 cases) and non clinical pharmacist intervention group(30 cases). The drug metabolism-related gene CYP3A5 was detected in the clinical pharmacist intervention group before administration, while they were not detected in the non-clinical pharmacist intervention group before administration. A total of 42 patients completed the study, including 22 in the clinical pharmacist intervention group and 20 in the non-clinical pharmacist intervention group, using the decision tree model to analysis the cost-effectiveness of treatment regimens of two groups. RESULTS After 6 months of treatment, there was statistical significance in the compliance rate of tacrolimus plasma concentration between the two groups(P<0.05). There was no significant difference in the total effective rate between the two groups. The expected costs of the clinical pharmacist intervention group and the non-clinical pharmacist intervention group were 10 261 yuan and 9 922 yuan, respectively. The cost-effectiveness ratios were 132.78 and 198.44, respectively. CONCLUSION Clinical pharmacists guide the tacrolimus individualization by participating in CYP3A5 gene detection, which improves the compliance rate of tacrolimus blood concentrations in patients with IMN and treatment effectiveness. And cost-effectiveness analysis showed that in the treatment process of tacrolimus for IMN, clinical pharmacists participate in CYP3A5 genotype detection to guide the individualized administration of tacrolimus is more economical and effective.