Abstract: High Performance Liquid Chromatographic (HPLC) method was employed for the determination of fanchinoline and tetrandrine in plasma of rats. The plasma sample was precipitated with acetonitrile and the supernatant was diluted and then directly injected into ODS C18 column with acetonitrile-phosphate buffer-triethylamine (80∶30∶0.3,V/V/V) as the mobile phase. UV detection was set at 282 nm and standard curve was for the quantification. This assay could be used for separation and determination of fanchinoline and tetrandrine in the bioactivity organism simply and accurately.