CONJUGATED DIENE RUBBER COMPOSITION FOR TIRE USE AND TIRE

A conjugated diene rubber composition for use in tires which comprises: (i) 2 to 100 parts by weight of a high-cis conjugated diene polymer which is a polymer of a conjugated diene monomer alone or with a copolymerizable monomer of another kind and has a cis bond unit content of 40% or higher based on the conjugated diene monomer units and a weight-average molecular weight (Mw) of 20,000 to 10,000,000, and in which the ratio (Mw/Mn) of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) and the weight-average molecular weight (Mw) satisfy the following relationship 1: log(Mw/Mn)