Objective To study the effect of Tibetan medicine Zuotai on in vivo pharmacokinetics of crocin-1 in rats.Methods After im injection of crocin-1 (5 mg/kg) in control (continuously ig normal saline for 7 d) and expermental (continuously ig Zuotai suspension for 7 d or 21 d) rats,The plasma concentration of crocin-1 was determined by RP-HPLC,and plasma concentration-time data were analyzed by DAS 2.0 software to get the related pharmacokinetic parameters of crocin-1.Results After continuously ig administration of Zuotai [10 mg/(kg?d)] for 7 d and 12 d in experimental rats,the pharmacokinetic parameters of crocin-1 changed significantly.The AUC,Cmax,and MRT were significantly greater in experimental rats than those in control rats,and the CL and Vd were significantly lower than those in control rats,and the AUC of crocin-1 was greater in the 21 d administration group than that in the 7 d administration group.Conclusion The result demonstrates that Tibetan medicine significantly affects the pharmacokinetics of crocin-1 in rats.After administration of Zuotai in rats,the absorption degree of crocin-1 is significantly increased and the clearance rate is significantly decreased.