Abstract: In order to search drugs for prevention and treatment of cardio-vascular diseases four species of Corydalis (C. stricta Steph, C. melanochlora Maxim, C lineariodes Maxim, C. mucronifera Maxim) from Qinghai plateau were studied. The total alkaloids were extracted with ion exchange resin method. Eleven alkaloids have been isolated by using column chromatography, preparative TLC and preparative HPLC. Among them, 9 alkaloids have been identified as d-hydrastine, acetylcorynoline, corynoline, d-adlumine, d-corlumidine, protopine, d-adlumidine, d-bicuculline and cheilanthifoline. Another two alkaloids are unknown.Their pharmacological tests are in progress.