Abstract: The deproteinization condition of neutral protease for welan gum and the effect of hydrolysis on welan gum properties were investigated. The conditions for neutral protease to hydrolyze protein in welan gum sample were optimized through the single factor and the orthogonal experiments.The optimal welan concentration,reaction temperature,p H and enzyme/substrate dosage of deproteinization were 1%,50℃,p H6.5 and 1m L/g,respectively.After hydrolysis for 6h under these optimal conditions,the deproteinization ratio was about 65.3%.The main component contents and apparent viscosity of welan gum samples were compared before and after the enzymatic treatment. Results showed that neutral protease reduced the protein content and increased the polysaccharide content,on the premise of maintaining the high-viscosity characteristic of welan gum.Deproteinization with neutral protease is an effective method to prepare welan gum sample with low protein and good properties.