Abstract: Salvianolic acid A (Sal A) is one of the most effective compounds isolated from the root of Salvia miltiorrhiza. Up to now, several studies regarding the pharmacokinetic profiles of Sal A have been reported, however there is no such study reported in monkeys, the species which is more similar to human. The aim of this study is to develop a LC-MS method for the determination of Sal A in monkey plasma and apply it to the pharmacokinetic studies of monkeys. After single intravenous administration of Sal A, the plasma concentration-time curves were observed and the main pharmacokinetic parameters were calculated. The plasma concentration at 2 min (C_{2 min}) values were (28.343±6.426), (45.679±12.301) and (113.293±24.360) mg·L^-1 for Rhesus monkeys treated with Sal A at 2.5, 5 and 10 mg·kg^-1. The area under the concentrationtime curve (AUC_0-∞) values were (3.316±0.871), (5.754±2.150) and (13.761±2.825) μg·L^-1·h, respectively. Furthermore, this method was improved and applied to the simultaneous determination of Sal A, Sal B and Sal C, which provided useful information for preclinical studies and clinical trials of Sal A, Sal B and Sal C.