Lactobacilli, one of the most common members of intestinal microbiota, have been applied and studied considerably. Because it can regulate the host intestinal microbiota balance and improve the immunity and resistance of host. Lactobacillus surface layer proteins (S-layer proteins) have been a research hotspot for playing an important role in the adhesion to the host. Here we summarize the advances in researches about the structure, the method of separation and purification, the situation of gene cloning and the probiotic functions of S-layer protein.