The thermal properties of chloroprene rubber (CR) with $^{60}Co;{gamma}$-ray irradiation has been investigated. The prepared CR was irradiated up to 1000kGy radiation dose by $^{60}Co;{gamma}$-ray and the radiation degradation of CR was investigated by thermogravimetric analysis and differential acanning calorimetry. Dynamic mechanical properties measurement and FT-IR observation are carried out as well. From these analyses results, the glass transition temperature($T_g$), decomposition onset temperature(DOT), oxidative induction time(OIT), the peak temperature of loss modulus and mechanical tan ${delta}$ values were compared for the radiation degradation level of CR. The tendency between $T_g$ and peak temperature of loss modulus and mechanical tan ${delta}$ agreed well with radiation doses. Decomposition temperature, OIT and DOT showed the same tendencies as increasing radiation doses. It was verified that these analyses are available to estimate the degradation level of CR.