Abstract: Gelatin-pullulan-based film is a water-soluble package material. The effect of relative humidity on mechanical properties, water-vapor transmission ratio, oxygen transmission ratio, oil transmission ratio, color and water solubility of gelatin-pullulan-based film were evaluated, and the effect of relative humidity on properties of gelatin-pullulan-based film, gelatin film and pullulan film were compared. The relative humidity of 80% lowered the tensile strength of gelatin-pullulan-based film, improved its flexibility, and showed no significant different on its oxygen resistance, oil resistance and transparency. The properties of gelatin-pullulan-based film were better than that of gelatin film and pullulan film in the same relative humidity.