The catalytic performance of catalyst,which was formed in situ from RuCl3-TPPTS[TPPTS:P(m-C6H4SO3Na)3],for slelctive hydrogenation of carbon-carbon double bond in acrylonitrile to prepare propionitrile were studied in biphasic system (aqueous/organic phase).Good conversion and excellent selectivity were obtained.We studied the effect of KOH/Ru(molar ratio),H2 pressure,P/Ru(molar ratio),concentration of Ruthenium,temperature and reaction time on the catalytic activity and selectvity.The results show that the catalytic system have good conversion and very high slectivity for the hydrogenation of carbon-carbon double bond of acrylonitrile at the same time,the catalyst were separated readily from the product.