To optimize the processing of phosvitin extraction from the delipidated duck egg yolk protein powder and increase the extraction rate,the response surface methodology with four factors at three levels was adopted. By measuring the yield of phosvitin,the effect of sodium chloride concentration,ratio of liquid to solid,extraction time,and the washing time on the yield of phosvitin was investigated. The experimental results showed: the order of various factors affecting the yield of phosvitin was: washing time > ratio of liquid to solid > extraction time > sodium chloride concentration. The theoretical maximum yield of phosvitin was 5. 47%. the optimum conditions,which were suitable for extracting phosvitin by using sodium chloride solution,were as follows: sodium chloride concentration of 12%,extraction time 5h,ratio of liquid to solid of 12: 1,5 times of washing. Under the above optimal extraction conditions,the yield of phosvitin was 5. 27% and the extraction rate was 88. 16%.