Objective To study the effect of amlodipine on the pharmacokinetics of bisoprolol in rats. Methods Twelve rats were randomly divided into two equal groups:A and B.Rats of group A were given bisoprolol.Rats of group B were given bisoprolol and amlodipine.Blood samples were taken from the animals for the determination of the plasma concentration of amlodipine by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS).The pharmacokinetics parameters together were calculated using DAS program to evaluate each of the two preparations and the pharrnacokinetic parameters were statistically compared. Results The main pharmacokinetic parameters of the two groups were as follows: C_max: (513.36?56.02) and (585.21?77.52) ng/ml, t_1/2: (1.30?0.51) and (1.51?0.65) h, AUC_0-t: (433.70?50.98) and (721.16?218.09) ng/(h穖l), CL/F: (38.02?5.63) and (25.9?5.18) L/(h穔g).The pharmacokinetics parameters of AUC_0-t and CL/F showed significant difference between the two groups(P<0.05). Conclusions The LC-MS/MS method is specific and sensitive.The amlodipine has significant effect on the pharmacokinetics of bisoprolol with extending of absorption and excretion in rats.