Abstract: The pharrnacokinetics and pharmacodynamics of changrelin (CRL) were studied in 7 dogswith arrhythmia induced by coronary artery ligature. The ECG and the percentage of reduction ratio ofventncular premature were used to evaluate the effect of CRL, and an HPLC method was used to determinethe serurn dnig concentration. A phannacokinetic program was used to fit concentretion-time (C-T) dataand a combined phannatvikinetic-phannacedynamic model was used to analyze effect-time ( E - T) data inindividual dogs. Mfter infusion with CRL 83 . 33 μg.kg^-1.min^-1 for 60 min, it was found that K₁₀, T_1/2,Vd, Cl and Ce were 0.0087 min^-1 , 78.03 min, 40.55 ml.kg^-1 , 0.42 ml.kg^-1. min^-1, and 2.01μg. ml^-1, respectively.