Abstract: In order to explore optimal methods of protein recovery from surimi wastewater and purify the wastewater, isoelectric precipition of proteins in surimi wastewater was studied.After properties such as pI values of proteins in surimi wastewater were determinated firstly, protein precipition was investigated varying pH, acid type and ionic strength.And then fractional isoelectric precipitation was tried to increase total recovery of protein.Results showed that pI values were near the points 4.3 and 5.9 respectively.Polybasic acid and higher ionic strength increasing were of advantage to precipition.And 74.36% recovery was obtained by fractional isoelectric precipitation, which was higher than traditional method with recovery above 60%.All the results supplied basic data to protein recovery technology, and broadened considerations for protein recovery and wastewater purification.