Aim: To establish a population pharmacokinetic modeling of rocuronium in geriatric patients undergoing surgery. Methods: Blood samples were collected after administration of rocuronium and the relevant datas were collected. The plasma concentrations of rocuronium were determined by UPLC-MS/MS method. The collection time of the sample is set as the independent variable and the plasma concentration of rocuronium as the dependent variable; all the significant effects were included in covariates. The covariates affecting the pharmacokinetic parameters of rocuronium in geriatric were quantitatively investigated through the nonlinear mixed effect model by Phoenix WinNonlin 8.3 software. Results: The final model is consistent with the three-compartment model, and the residual model is proportional as residual model. The final model formula is as follows: V=tvV*exp(nV)，V2=tvV2，V3=tvV3；Cl=tvCl*ALB∧dCldALB*Urea∧dCldUrea*exp(nCl)，Cl2=tvCl2，Cl3=tvCl3.式中tvV=1.313L，tvV2=0.762L，tvV3=1.043L，tvCl=0.041L/h，tvCl2=3.238L/h，tvCl3=0.618L/h，dCldALB=1.015，dCldUrea=0.360.The final model shown that ALB and Urea are covariates that could affect the clearance rate of pharmacokinetic central Compartment. The validation and prediction results had shown a good stability. Conclusion: The results suggest that ALB and Urea might affect rocuronium clearance rate. Pharmacokinetic parameters can be personalized according to the actual situation of patients, which can provide reference for the adjustment of rocuronium medication and pharmaceutical care plan in clinical treatment of geriatric surgery, to ensure the safety and postoperative recovery of geriatric during operation.