Abstract: The defatted soybean meal was used as raw materials,and suffered liquid fermentation by Lactobacillus.Then soybean protein was extracted from fermented solubility. The emulsification,emulsion stability,gel strength,water holding capacity,oil holding capacity and some other functional properties of soybean protein were determined. The results indicated that the solubility,EAI,gel strength,water holding capacity and oil holding capacity were significantly improved after fermentation( p < 0.05),ESI was significantly lower( p < 0.05) while the water holding capacity and the oil holding capacity had little changes during this process. SDS- PAGE electrophoresis demonstrated that soy protein after fermentation emergence of new bangs between 29.0~44.3 ku,high molecular weight proteins of soybean were degraded into small molecular weight proteins,among which fermentation had a greater impact on the 7S component and less impact on the 11 S component.The test showed that lactobacillus can effectively improve the functional properties of soy protein.