Abstract: Harringtonine and homoharringtonine are the potent antileukemic alkaloids, which were isolated from some species of Cephalotaxus. Recently the variation of the relative contents of these two alkaloids in the species of C. fortunei Hook. f. and C. sinensis (Rehd. et Wils.) Li were investigated. By assaying different parts of these two plants, the double alkaloid (harringtonine, homoharringtonine) contents were showed: the leaves with twigs was 0.0167%, barks 0.014%,stems 0.008%, roots 0.0251%, seeds 0.0296% in C. fortnnei and the leaves with twigs 0.0136%, barks 0.0134%, stems 0.0113%, roots 0.0174%, seeds 0.030% in C. sinensis. The variations of the relative alkaloid contents in monthly average were also described in this paper.

Key words: Cephalotaxus sinensis, C.fortunei, Harringtonine, Homoharringtonine