The segregation structure and the gradient structure of poly(2-ethylhexylacrylate) (P2-EHA)/poly(vinylidene fluoride-co-hexafluoro acetone) [P(VDF-HFA)] blends were confirmed by ATR-FTIR and SEM. For the P2-EHA/P(VDF-HFA) (50/50) blend, the P(VDF-HFA) and P2-EHA layers were observed at the free surface side and bottom side, respectively. The gradient structure was obtained for the P2-EHA/P(VDF-HFA) (30/70) blend. The domain morphology of a cross section of the P2-EHA/P(VDF-HFA) (50/50) blend was dramatically changed by the thickness of the blend film. Finally, we propose that the segregation structure and gradient structure formed in P2-EHA/P(VDF-HFA) blends were caused by surface tension difference, rate of phase separation, rate of solvent evaporation, and molecular weight difference.