Sprague-Dawley rats were given ig tetramethylpyrazine phosphate (TMP) 5 mg/kg with or without previous borneol 5 mg/kg. The plasma TMP concentrations were analysed by GC method, and the data were treated by NONLIN program. The Cmax were 931 and 562 ng/ml, respectively, (P less than 0.01); while the AUC were 68,849 and 37,174, respectively, (P less than 0.05). It is suggested that the borneol enhances the absorption of the TMP but not in elimination.