Croton crassifolius Geisel belongs to the genus croton of the family euphorbiaceae. By means of solvent extraction and repeated chromatorgraphy on silica gel, Sephadex LH-20 and HPLC, the ethanol extract of the roots of Croton crassifolius Geisel was chemically investigated, which led to the isolation of nine diterpenoids. By using spectroscopic analysis, their structures were identified as follows： Crassifolin P（1）, Crassifolin J（2）, 1,5,6-trimethyl-5-（2-（5-oxo-2,5-dihydrofuran-3-yl）ethyl）-1,2,3,4,5,6,7,8-octahydronaphthalene-1-carboxylate（3）, Penduliflaworosin（4）, isoteucvin（5）, Crassifolin G（6）, teucvin（7）, Chettaphanin I（8）, mallotucin D（9）. Among of them compound 1 was a new compound.
In the present research, in order to study the chemical constituents ofPaliurus ramosissimus （Lour.） Poir., the isolation of its ingredients was performed by repeated chromatography on silica gel, Sephadex LH-20, ODS and preparative HPLC. Their structures were elucidated on the basis of combination of mass spectrometry and 1D, 2D NMR spectroscopy. A total of 8 compounds were obtained, and their structures were identified as 313-hydroxy-27-（3,4-dihydroxybenzoyl）oxylup-20（29）-en- 28-oic acid （1）, betulinic acid （2）, lupeol （3）, 27-O-trans-caffeoylcylicodiscic acid （4）, ceanothic acid （5）, 24-hydroxyceanothic acid （6）, dihydrokaempferol （7）, eriodictyol （8）. Among them, compound 1 was a new compound. Compounds 3-4, 7-8 were isolated from Paliurus ramosissimus （Lour.） Poir. for the first time.
