Abstract: The application of foam fractionation in recovery of lactoalbumin from soy protein wastewater was studied. The influence of various operation parameters was also investigated. The experimental results showed that the effect on separation was differently influenced by pH，gas velocity，initial feed concentration，pool height and foam height. Low gas velocity，high foam level，low initial concentration，and appropriate pH were the optimum conditions. The enrichment ratio could reach 3.25 when concentration of feed was 0.54 g/L，pH was 5，ratio between foam height and pool height was 4∶1，gas velocity was15.0 L/h. When concentration of feed was 0.54 g/L，pH was 5，ratio between foam height and pool height was 3∶1，gas velocity was15.0 L/h，the highest value of removal rate obtained was 48.5%.