Abstract: The selective hydrogenation of the C C bonds in acrylonitrile-butadiene rubber(NBR),using a new Rh-Ru based bimetallic single ligand catalyst(BMSC),was examined.Gel free products with a high degree of hydrogenation were obtained,indicating a degree of activity and selectivity equal to RhCl(PPh 3) 3 for this new less expensive catalyst.The concentration of NBR solution and the amount of the second-ligand L 2 could affect the degree of hydrogenation.It was found that 7.0×10 ^-2 g·ml ^-1 NBR solution and 1.5% second-ligant L 2 based on the amount of NBR were appropriate.An experimental design to study the effect of temperature,hydrogen pressure,catalyst concentration and reaction time on the degree of hydrogenation was developed and subsequently carried out.The resulting optimum technological parameters were defined.When the catalyst concentration was 0.25%,temperture 145℃,hydrogen pressure 1.2MPa,reaction time 4h,the degree of hydrogenation reached over 98%.