Abstract: A conjugated diene polymer composition comprising: (a) 100 parts by weight of a non-coupling conjugated diene polymer consisting of at least one conjugated diene or a non-coupling random copolymer consisting of a conjugated diene and at least one monovinyl aromatic compound, (b) 0.03 to 0.2 parts by weight of a sulfur-containing phenol type antioxidant represented by the following general formula (I): wherein R1 and R3 are —CH2—S—R5 in which each R5 represents independently an alkyl group having 2 to 18 carbon atoms; R2 represents hydrogen or a methyl group; and R4 represents an alkyl group having 1 to 8 carbon atoms, and (c) 0.03 to 0.2 parts by weight of a phenol type antioxidant represented by the following general formula (II): wherein R6 represents a tert-butyl group and R7 represents an alkyl group having 2 to 22 carbon atoms.