Abstract: OBJECTIVE To investigate the plasma drug concentration and pharmacokinetic parameters in rats after intravenous injection of irinotecan liposome, and to evaluate the pharmacokinetic characteristics of irinotecan liposome compared with irinotecan injection. METHODS The dosages of irinotecan liposome injection were 5, 10 and 20 mg·kg^-1, respectively. The dose of irinotecan injection in the control group was 20 mg·kg^-1. The HPLC method was used to detect the irinotecan content in the rat plasma. The pharmacokinetic parameters were calculated by the non-atrioventricular model of the pharmacokinetic template in DAS 3.0 software. The statistical analysis of pharmacokinetic parameters was carried out with SPSS 18.0 software. RESULTS The control solution of irinotecan in plasma was well linear in the range of 0.20-100.02 μg·mL^-1, r=0.999 3. Compared with irinotecan injection at the same dose, the plasma peak concentration C_max of the irinotecan liposome was significantly increased(82 times), the average residence time MRT_(0-t) was significantly prolonged(14.6 times), the half-life t_1/2 was prolonged(6.5 times), and the total irinotecan plasma exposure was greatly increased(748.5 times). And they had significant difference by statistics analysis. CONCLUSION Compared with irinotecan injection, the pharmacokinetics of irinotecan liposome are significantly improved, may enhance the efficacy of irinotecan.