Abstract: AIMTo develop an HPLC method for the determination of crocetin in rat plasma and study the pharmacokinetics in rats. METHODSHypersil C₁₈ column (5 μm, 4.6 mm×200 mm) was used at column temperature 30℃. The mobile phase consisted of methanol-water-acetic acid (75∶24.5∶0.5) at the flow rate of 1.0 mL·min^-1. The UV detection wave length was 423 nm. RESULTSThe calibration curve was linear (γ=0.9996) in the range from 0.49 μg·mL^-1 to 7.87 μg·mL^-1 for crocetin. The mean recovery was 105.2%. The lowest detectable concentration of crocetin was 0.14 μg·mL^-1 (S/N=3). The RSDs of within-day and between-day were all less than 5%. The plasma crocetin was steady. The HPLC method of determination of crocetin in the plasma was established. After single dose of 50 mg·kg^-1 ig in 10 rats, the main pharmacokinetic parameters were estimated as follows: T_1/2α (30±6) min, T_max (65±16) min, C_max (5.0±1.0) μg·mL^-1, AUC_0-T (845±109) μg·min·mL^-1, V_d (5.0±0.8) L·kg^-1. Crocetin was shown to be absorbed into the blood through the gastrointestinal tract. CONCLUSIONThis method is quick, precise and reliable. Crocetin was shown to be quickly absorbed in rats.