Abstract: In a process for hydrogenating a conjugated diene polymer which comprises hydrogenating the carbon-carbon double bonds of the conjugated diene polymer using a hydrogenation catalyst supported on a carrier, the improvement wherein the carrier is porous silica having an average pore diameter of from 80 to 1,200 .ANG. and a specific surface area of not more than 600 m.sup.2 /g.

Abstract: A process for producing a hydrogenated conjugated diene polymer, which comprises hydrogenating the carbon-carbon double bonds of a conjugated diene polymer in a solvent using a supported catalyst composed of a hydrogenating catalyst supported on a carbon carrier having an average particle diameter of 5 m.mu. to 10.mu. and a specific surface area of 5 to 2000 m.sup.2 /g, and after the hydrogenation reaction has been completed, separating and recovering the hydrogenated conjugated diene polymer from the solution of the hydrogenated polymer without separating the catalyst therefrom.

Abstract: In a process which comprises catalytically hydrogenating the carbon-carbon double bonds of a conjugated diene polymer, the improvement which comprises using a catalyst composed of a porous powdery or granular carrier and supported thereon both Pd and at least one metal selected from the group consisting of the metals of Groups Ia, IIa, IIIa, IIIb, IVa, Va and VIa of the periodic table, Ge and Sb.