The surface of  barium titanate (BaTiO3) nanoparticles was modified by the plasma treatment with a varied working pressure from 20kv to 24kv for improving the interaction between ferroelectric polyvinylidene fluoride (PVDF) and BaTiO3 nanoparticles. The nanocomposites of PVDF with unmodified and modified BaTiO3 (80/20) were prepared by the solution method. The BaTiO3 particles in unmodified composites existed almost aggregates together and not homogeneous dispersion due to intrinsic incompatibility. In contrast, most of the BaTiO3 nano-particles in the modified composites were clearly welldispersed in the PVDF matrix. Unapparent and smooth interface between nanopartixles and the PVDF matrix in the modified composites suggested that the interface adhesion between nanoparticles and matrix was drastically improved in the presence of the functionalized BaTiO3. For the treated PVDF/BaTiO3 film, the value of the water contact angle was scarcely changed when the working pressure under 20kv. However, the water contact angle of treated film with 22kv was greatly decreased to 79.1°. For the treated film with 24kv, the value of the water contact angle was further decreased to 68.4°. A remarkable increase in the amount of polar β phase of PVDF has been observed upon dispersion of modified BaTiO3 nanoparticles in the PVDF matrix. It is attributed to the better dispersion of modified BaTiO3 nanoparticels in the PVDF matrix.