It has been reposed (8, 9, 10) that by boiilng sulfonic acid type ion exchage resin with certain plant drugs, the alkaloids in the latter could be transferred quantitatively to the resin and could be determined subsequently In this paper a1e reported the results obtained with ion cxdlange resms nt sulfonic acid typc and an ion exchange fabric of phosphoric acid type Nine to ten kinds of plant drugs were studied in each casc Five uf theset Areca catechu L., Fritillaria thunbergii Miq., Stemona lobgroga Lout., Sopholra flavescens Ain. And Leonurus heteropbyllus Sweet, could be determined by ion exchange rCSIDS and tour, namelv. Atropa belladonna L., Areca calecku L., Leonurus hetcrophyUus Sweet and Coptis chinensls Franch, by thc ion exchange fabric. Where the method worked, it was simple ranid and gave the same results as those obtalned with the pharmacopeiacal methods.