A population pharmacokinetic model of cyclosporine (CsA) for clinical renal transplant patients was constructed to adjust CsA’s administration individually. A total of 2,548 retrospective drug monitoring data were collected from 120 Chinese renal transplant patients receiving CsA. Population modeling was performed with NONMEM by a one-compartment model with first-order absorption and elimination. Six significant covariates were included in the final model. It is postoperative days (POD), total bilirubin level (TBIL), current body weight (CBW), age, concurrent metabolic inhibitors of CsA (INHI), and hematocrit (HCT). The population means for CL/F (28.5 L/h), V/F (volume of distribution, 133 L), and inter-patient variability (CV%=19.7%) for CL/F were estimated. The model was further validated internally and externally, and was demonstrated to be effective and robust. Moreover, in order to put the result of population pharmacokinetic studies into clinical practice, a database with the name of C-TDM for post renal transplantation patients based on the population model was established. Up on the availability of the information from clinic, the precision of the plasma concentration predicted with C-TDM was classified into 3 levels, they are population, sub-population and individual. C-TDM’s interface is user-friend, and the median value, the 90% confidence interval are simulated accompanied with comprehensive graphs, to facilitate the individualized application of CsA. A population of pharmacokinetic model of cyclosporine (CsA) for clinical renal transplant patients was constructed to adjust CsA’s administered individually. A total of 2,548 retrospective drug monitoring data were collected from 120 Chinese renal transplant patients receiving CsA. Population modeling was performed with NONMEM by a one -compartment model with first-order absorption and elimination. Six significant covariates were included in the final model. It is postoperative days (POD), total bilirubin level (TBIL), current body weight (CBW), age, concurrent metabolic inhibitors of CsA The population means for CL / F (28.5 L / h), V / F (volume of distribution, 133 L), and inter-patient variability (CV% = 19.7%) for CL (INHI), and hematocrit The model was further validated internally and externally, and was demonstrated to be effective and robust. Moreover, in order to put the result of population pharmacokinetic studies into clinical practice, a database with the nam e of C-TDM for post renal transplantation patients based on the population model was established. Up on the availability of the information from clinic, the precision of the plasma concentration predicted with C-TDM was classified into 3 levels, they are population, sub -population and individual. C-TDM’s interface is user-friend, and median value, the 90% confidence interval are simulated accompanied with comprehensive graphs, to facilitate the individualized application of CsA.