The study aimed to improve barrier of PCL film against oxygen and water vapor. The PCL/PPC composite films were prepared by melt blend via twin-screw extrusion. The miscibility, thermology, barrier and mechanical properties of the PCL/PPC composite film were investigated. With the addition of a small or a large amount of PPC, the PCL/PPC blends showed good miscibility. But blends with moderate PPC contents presented phase separation. The penetration coefficient of oxygen and the penetration rate of water vapor showed linear decrease with the increase of PPC content. With addition of PPC, PCL presented higher modulus and strength. The composite film showed better tear resistance at low blending ratio. The PCL film exhibited much better barrier properties against oxygen and water vapor and relative higher mechanical strength with suitable addition of PPC.