The latex of Asclepias curassavica L. was shown to contain 40-60"1 cardenolides and 0.4-0.6" 1 esterified triterpenes. The dynamics of 14C incorporation of D-glucose-U-14C, acetate-l-14C and mevalonate-2-l4C into esterified triterpenes and cardenolides in excised stem parts have been studied. The results obtained indicate that glucose is a very effective precursor in latex triterpene synthesis. The three precursors used were only slightly involved in cardenolide synthesis, The results are discussed in relation to the view that both latex constituents probably have different sites of synthesis.