Lactobacillus casei is a probiotic that can colonize in animal intestines.The recombinant L.casei was constructed to express human epidermal growth factor (hEGF) and to test if the bacterium has the potential of being used as live bacterial vector to express specific protein in situ to stimulate mucosal immunity.The hEGF was synthesized through splicing overlapping extension PCR (SOE PCR),and cloned into the LAB surface exhibition vector pELWH,yielding pELWH-hEGF.The plasmid resulted was electroporated into L.casei MCJΔ1.Transformants were then analyzed by Western blot and indirect immunofluorescent assay.Cell proliferation assay was used to investigate the bioactivity of hEGF expressed in L.casei.SlpA-hEGF fusion protein on the cell surface and in the supernatant was detected.The molecular weight of the SlpA-hEGF fusion protein was estimated to be approximately 55 ku.The result of cell proliferation assay showed that the SlpA-hEGF fusion protein and the supernatant can stimulates the proliferation of NIH/3T3 cells dramatically.It will lay the foundation for L.casei having the potential of being an excellent live vector for protein delivery.