Solid state nuclear magnetic resonance was carried out by the continuous wave and pulse methods for butadiene/styrene (B/S) triblock copolymers containing various amounts of epoxy groups. The effects of epoxidation on the second-order phase transition and molecular motion were examined. It was found that, with an increase in epoxy unit content from 0 to 0.31 groups 100 g copolymer, the glass transition temperature, T g, in polybutadiene matrix increased from 201 to 264 K. The main minimum of the spin-lattice relaxation time was also shifted to higher temperatures. The activation energy determined from the slope of the low temperature curve T 1 = f( 1 T ) was found to be 1.7 times higher in epoxidized copolymer containing 0.25 mol epoxy groups 100 g than in pure B/S copolymer.