AIM To study the chemical constituents from the dregs of Euphorbia Alatavica Boiss.METHODS The acetone-methanol extract from the dregs of E.Alatavica was isolated and purified by silica,Sephadex LH-20 and preparative-HPLC column,then the structures of obtained compounds were identified by physicochemical properties and spectral data.RESULTS Nine compounds were isolated and identified as 8-hydroxy-3-methoxy-5H-pyrido [2,1-d] pyrazin-5-one (1),isoscopoletin (2),dihydroapigenin (3),β-carboline alkaloid (4),syringaresinol (5),pinoresinol (6),methylparaben (7),methyl-3,4-dihydroxybenzoate (8),trimethyl3,4-dehydrochebulate (9).CONCLUSION All the compounds are isolated from this plant for the first time,compound 1 and 4 are isolated from the genus Euphorbia for the first time.