Abstract: Some crucial physiological and biochemical parameters including the carbohydrate and protein in the young stems of four crops of Euphorbiaceae with different cuttage ability were studied in this paper, which had great significance to explore the cuttage mechanism of Euphorbiaceae. The soluble sugar and starch content was analyzed by phenol method, the soluble protein content was examined by Bradford method, and starch distribution of young stems was investigated by paraffin section and periodic acid-schiff staining. The results showed that young stems of‘SC5’(Manihot esculenta crantz) (with a high cuttage ability),‘Clone1’(Jatropha curcas) (with a high cuttage ability), and‘WH14’(Manihot esculenta sub. spp. flabellifolia) (with a poor cuttage ability) had high concentration of soluble sugar, and that of‘SC5’and‘Clone1’had high concentration of starch, but that of‘Reyan7-33-97’(Hevea brasiliensis) (with a poor cuttage ability) had the lowest concentration of soluble sugar and starch in them. Young stems of‘WH14’and‘SC5’contained significantly higher concentration of soluble protein than that of‘Clone1’and‘Reyan7- 33- 97’. Periodic acid- schiff staining revealed that the starch in young stems of these four crops distributed differently. The cortex and phloem of‘Clone1’and the primary xylem of‘SC5’stored much starch in their young stem. However,‘Reyan7-33-97’and‘WH14’only stored a little starch in the phloem. These results suggested that high starch content in young stems of Euphorbiaceae might be essential in cuttage of Euphorbiaceae, and protein concentration in cutting stems of Euphorbiaceae might be not related to cuttage.