C-13 and Xe-129 high-pressure (HP) magic-angle spinning WAS) NMR was applied to a polystyrene/poly(vinyl methyl ether) (PS/PVME) = 50/50 blend under Xe pressure range of 0.0-4.0 MPa for investigating effects of the dissolved Xe atoms on the segmental motions of the individual component polymers. It is shown that the chemical shift of 129Xe dissolved in the blend moves to the high-frequency side and the line becomes narrow with increasing Xe gas pressure. The 129Xe higher-frequency shift is explained in terms of an increase of the Xe concentration in the blend. The line narrowing suggests that the Xe atomic diffusion is enhanced with increasing Xe concentration in the blend. On the other hand, the C-13 line widths under MAS and H-1 dipolar decoupling (DD) evidently show that the dissolved Xe atoms enhance the segmental motions of the individual component polymers (plasticization effect) at Xe gas pressures higher than 1.0 MPa. Furthermore, the observed pressure and temperature dependence of the line widths demonstrates that the motional frequency difference between PS and PVME at high pressures is less than that observed at high temperatures. It is concluded that the dissolved Xe atoms not only enhance the segmental motions of PS and PVME but also work to reduce the motional heterogeneity in the blend.