Objective:To deliver oxyntomodulin (OXM) to the food-grade strains of Lactctococcus Lactis (L.lactis), and identify its expression level in vivo and in vitro. Methods: L.lactis was transformed with recombinant plasmid pNZ8149-OXM by electroporation, and oxyntomodulin expression was detected by Western blot. Then, pNZ8149-OXM-transformed L.lactis was administered orally to mice, and OXM were detected by HPLC-MS from serum samples. Results: The expression of recombinant OXM from the pNZ8149-OXM-transformed L.lactis reached a maximum at 5 h after induction with nisin. The level of OXM in the serum of mice fed with pNZ8149-OXM-transformed L.lactis was 2.5 times higher than that in the control group. Conclusion: The recombinant L.lactis expressing oxyntomodulin is successfully constructed and expressed. It provides the basis for further study on the effect of reducing weight and lipid.