Abstract: OBJECTIVE To investigate the accuracy of Java PK^® for Desktop(JPKD) in predicting the blood concentrations of tacrolimus in patients after renal transplantation and to analyze the factors affecting the accuracy of the prediction. METHODS A retrospective analysis method was used. Data of patients using tacrolimus to anti-rejection therapy after renal transplantation from September 2019 to January 2020 in Jinling Hospital, Nanjing University School of Medicine were collected. The absolute weight deviation and relative prediction error between the measured concentration and the predicted concentration were calculated by using JPKD to predict tacrolimus dose-adjusted plasma grain concentration, and the prediction ability of JPKD was evaluated. The univariate and multivariate Logistic regression analysis were used to screen the influence factors of JPKD prediction accuracy. RESULTS A total of 101 patients’ blood concentration data were collected from 31 patients. The average predicted concentration of tacrolimus was (6.91±2.65)μg·L^-1 (2.39-15.18 μg·L^-1), and the average measured concentration was (8.99±4.13)μg·L^-1 (2.70-22.00 μg·L^-1), with an average absolute weight deviation of 28.46% and an average relative prediction error of -15.87%. The absolute weight deviation of prediction results <30% accounts for 57.14%. Univariate Logistics regression analysis showed that gender, height, hematocrit, CYP3A5 genotype, and the combined use of posaconazole were associated with inaccurate prediction results. Multivariate Logistics regression analysis showed that the CYP3A5 genotype and the combined use of posaconazole were the main risk factors for inaccurate prediction. CONCLUSION JPKD system has a certain predictive ability for blood concentration of tacrolimus. In clinical application, it is necessary to combine JPKD system with the CYP3A5 genotype and the combined medication to develop an individualized drug therapy plan.