Lactobacillus L15, a strain of Lactobacillus sp. isolated from the intestinal tract of healthy Paralichthys olivaceus, and Lactobacillus acidlophilus ATCC4356 were used to investigate their specific adhesions. It was shown that cell surface proteins of two strains could be extracted by 5 mol/L lithium chloride( LiCl). Two surface proteins with molecular weights of 61.8 kDa and 54.6 kDa were identified to mediate the adhesion to intestinal mucus of Paralichthys olivaceus and Common carp respectively by the method of Western blotting, and the two novel proteins were named as MAPPpo1 and MAPPcc. In Lactobacillus acidlophilus ATCC4356, two proteins of 43.0 kDa and 63.3 kDa were identified to mediate the adhesion to intestinal mucus of Paralichthys olivaceus. Nevertheless, only 43.0 kDa protein was identified to mediate the adhesion to intestinal mucus of Common carp. Furthermore, the mucus proteins which participated the adhesion as the bacteria receptors were identified by the same method and it was found that L15 and ATCC4356 had the same receptors.There were 29.7 kDa and 30.3 kDa proteins in the intestinal mucus of Paralichthys olivaceus and only the 26.2 kDa protein was testified in the intestinal mucus of Common carp. It is demonstrated that the adhesion of Lactobacillus to mucus is dependent on the strain specificity, as well as host specificity.