OBJECTIVE This study was designed to find out the impact of micro-ecological environment on the incidence of allergic rhinitis after developing a model of allergic rhinitis on mice. METHOD Sixty mice were randomly divided into GF group (n=30) and SPF group (n=30). Mice of GF group were fed in the germ-free environment and mice of SPF group were fed in the specific pathogen-free environment. Then each group were randomly divided into model group (20 mice) and control group (10 mice). Establish allergic rhinitis model in the mice of model group using ovalbumin (OVA) at the age of 6 weeks, observe and score the corresponding symptoms and signs that could been induced. Stain with hematoxylin eosin (HE) staining method for nasal mucosa to observe the morphological changes. Using enzyme linked immunosorbent assay to detect the concentration of IgE, IFN-γ and IL-4 in the peripheral blood serum. RESULT The chi square test showed that the incidence of allergic rhinithis in the mice of GF group was significantly higher than that in the SPF group (P< 0. 05). HE staining showed that the nasal mucosas of allergic rhinitis positive reaction mice were highly congestive and edematous and had a large number of inflammatory cell infiltration, while there was no abnormal morphology of nasal mucosas in mice with no allergic rhinitis reaction. EOS counting displayed that the number of eosinophilic cells in nasal mucosa of positive allergic rhinitis reaction mice was increased significantly. The concentration of IgE and IL-4 in the serum of positive allergic rhinitis reaction mice was highly increased (P <0. 05), and IFN-γ was significantly decreased (P< 0.05). CONCLUSION The difference of micro-ecological environment may play a key role in the occurrence of allergic rhinitis in mice.