PRODUCTION OF DIENE POLYMER

PURPOSE:To obtain easily the titled highly stereoregular polymer having unsaturated side chains in a high proportion, by polymerizing a conjugated diene in the presence of a catalyst system, prepared by bringing a Co compound into contact with a specific organometallic compound, etc. in the presence of a conjugated diene, and adding carbon disulfide, etc. thereto in an aqueous system. CONSTITUTION:A conjugated diene, e.g. butadiene, is polymerized in the presence of a catalyst system, prepared by bringing (A) a cobalt compound, e.g. cobalt octylate, previously into contact with (B) an organometallic compound of a metal selected from Groups I -III in the periodic table, e.g. triisobutylaluminum, or a hydride thereof in the presence of the conjugated diene in a molar amount of 1-100 times of that of the component (A), and incorporating the resultant catalyst with one or more of carbon disulfide, phenyl isothiocyanate and a xanthogen compound in an aqueous system to afford the aimed polymer.