Conjugated Diene-Based Polymer, Branching Agent, Production Method for Conjugated Diene-Based Polymer, Oil Extended Conjugated Diene-Based Polymer, Rubber Composition, and Tire

A conjugated diene-based polymer of the present invention has a branch number (Bn) measured by viscosity detector-equipped GPC-light scattering measurement of 8 or more, has a change (ΔT) of an oxidation onset temperature caused through application of a thermal load of 11.9° C. or less, and contains an aromatic vinyl compound monomer unit.