Mechanical properties and gas permeability of biodegradable pectin/Starch-montmorillonite clay (filler) have been studied. Tensile strength and modulus was increased as the increasing content of montmorillonite. X-ray diffraction was used to assess the periodic distance of the clay layers and transmission electron microscopy was used to observe the composite morphology. The periodic distance of the stacks was 21.76 ~ 26.12 A for the processed composites. Thus suggests that the layers of the clay particles have been intercalated. Oxygen permeability of pectin/starch-clay composites was generally lower than that of plastic films.