The biological edible membrane is made by sodium alginate,Cryptococcus laurentii and other edible materials.Its properties,such as thickness,mechanical strength,water vapor transmission,oxygen permeability were studied.Then Gala apples dipped with the biological edible coating liquid.The result showed that the coating significantly decreased the weight loss,enhanced the fresh color of the apples,delayed the decline of hardness and vitamin C and the increased of malondialdehyde.The treated apples also maintained relatively high soluble solids,total sugar and titratable acidity.Further more,it inhibited the growing of Streptomyces and improved the sensory evaluation.Its preservative effect was obviously superior to the control group.Therefore,the study indicates that the biological edible sodium alginate coating containing Cryptococcus laurentii can improve the quality of postharvest storage of Gala apples.