Abstract: In this research,antioxidant activitiy of different fractions from ethanol crude extracts of S. henslowianum was investigated in vitro. The total phenolic contents of the 95% ethanol crude extracts and their four solvent fractions( viz.,petroleum ether( PE),ethyl acetate( EA),n- butanol and aqueous) were determined by Folin-Ciocalteu,and their antioxidant properties were evaluated using three assays including 1,1- Diphenyl- 2-picrylhydrazyl radical 2,2- Diphenyl- 1-( 2,4,6- trinitrophenyl) hydrazyl( DPPH),2,2'- Azinobis-( 3-ethylbenzthiazoline-6- sulphonate( ABTS) radical scavenging and oxygen radical absorbance capacity.The results showed that EA fraction had the highest content of total phenolics( 12.71 ± 0.02 mg gallic acid equivalents / g). All five fractions from S. henslowianum exhibited the antioxidant activity. EA fraction exhibited strongest antioxidant activities among all the fractions,which the values of IC_(50) based on DPPH· and ABTS+·were( 0.89 ± 0.01) mg /m L and( 0.73 ± 0.03) mg / m L respectively,and the values of ORAC was( 1803.78 ± 81.37) μmol Trolox equivalents / g.