Crystallization process and the phase structure formed in PEO/PPMA blends were measured by differential scanning calorimetry (DSC) and small angle X‐ray scattering (SAXS). The half time of the crystallization t1/2increased by blending PMMA and with PMMA molecular weight increased. 2 &thgr; at which the scattered intensity showed the maximum became small by blending PMMA and decreased with PMMA molecular weight increased.