Abstract: In order to study the influence of Sophora japonica extract（SJ） on the properties of polyvinyl alcohol（PVA） film, the PVA/SJ composite films were prepared by mixing Sophora japonica extract with different mass fractions with PVA as film-forming matrix and glycerin as plasticizer. The effects of the amount of SJ on the mechanical property, structure, color, barrier properties, thermal stability and oxygen permeability of PVA/SJ composite films were analyzed. The results indicated that the addition of SJ had little effect on the mechanical property of PVA film, but improved its thermal stability to a certain extent. When the content of SJ increased from 1% to 4%, the transmittance of the composite films decreased gradually. At 3% SJ, the shielding rate of the composite film to ultraviolet light almost reached 100%. The oxygen permeability showed a tendency rising up at the beginning and declining in late with the enhancement of SJ content. At 2% SJ, the oxygen permeability reduced from 3.52（cm~2·mm）/（m~2·d·atm） to 1.84（cm~2·mm）/（m~2·d·atm）. When the lard was packed with PVA/SJ composite films, the lard did not deteriorate after 40 days of storage, verifying that the composite films had a great antioxidative effect.