PbTiO3/PVDF nanocomposites were prepared via in-situ growth of nanosized PbTiO3 particles in PVDF matrix by sol-gel method. Nanosized PbTiO3 grown in the composites film was characterized by X-ray diffractometry (XRD) and transmission electron microscopy, and the dielectric properties of the composite films prepared were measured. The distribution of PbTiO3 nanoparticles in-situ grown in the PVDF matrix was examined using a scanning electron microscope. The relative dielectric constant increases with increasing the weight fraction of PbTiO3 in-situ grown. In particular, the dielectric loss monotonically decreases with the increase of PbTiO3 content at 1MHz.