Abstract: The suitable plasticizers were chosen to prepare zein film and the film forming conditions were optimized to improve the moisture resistance.For this purpose,glycerin was used as basic plasticizer,and the influences of propylene glycol,polyethylene glycol and citric acid on the mechanical properties and moisture barrier property of zein film were investigated.The result showed that zein film showed better mechanical properties and moisture barrier properties using citric acid as plasticizer,and the membrane moisture absorption rate and water vapor transmission rate were the lowest when citric acid was 0.1 g/g.On this basis of these results,effects of the ratio of glycerol,film forming temperature and ethanol concentration on the rate of moisture absorption and water vapor permeability of zein film were investigated.The results indicated that rate of moisture absorption (RA) and water vapor permeability (WVP) of film gradually increased with the addition of glycerol amount,the minimum value was observed when glycerin was 0.1 g/g;RA and WVP increased firstly and then decreased with the increase of film forming temperature,the minimum was at 60℃;RA and WVP decreased first and then increased with the increase of ethanol concentration,the minimum was at 70%.Response surface methodology was employed to optimize the film preparing conditions,and the result showed that the optimized conditions were as follows:the ratio of citric acid was 0.28 g/g,the ratio of glycerol was 0.11 g/g,the film forming temperature was 61.06℃,and the ethanol concentration was 65.04%.WVP of zein film prepared under these conditions was 6.28 g·mm·m^-2·d^-1·kPa^-1.These results indicated that citric acid could improve the moisture barrier property of zein film.