After we produced a fermented vegetable extract (OM-X) in which vegetables, fruits, seaweeds, mushrooms and other ingredients are fermented with lactic acid bacteria for a long time, we investigated the effect of OM-X against degranulation reaction using rat basophilic leukemia cells (RBL-2H3) as a mast cell model and passive cutaneous anaphylaxis (PCA) reaction using Type I allergy model mouse. The findings suggest that OM-X may be a material effective against Type I allergy.