Abstract: As a succession of the previous report¹,the comparative morphological andhistological st udies on the Chi n ese crude dr ug H uang Qi derived from the roots of Astragalus ernestii Comb,A.membranaceus (Fisch.)Bge.f.purpurinus (Y.C. Ho)Y,C,Ho,A.hoantehy Franch.,A.tanguticus Batalin and A.mahoschanicus Hand.Mazz.were carried out and illustrated with diagrammaticand detailed drawings.A table for comparison and a key for identification are also Dresented.It isshown from the resuIts that the following features are ot diagnostic significance for the differentiationof the crude drugs derived from the above five species,viz,(1)the arrangement and amount of thephloem fibers;(2)the shape of the cambium,whether it is continuous or interrupted,smooth orsinuous;(3)the arrangement of the xylem vessels and fibers,(4)the presence or absence of stonecells, ctc.