Abstract: To observe pathological and immunological changes of the lower airway in intranasal ovabumin induced animal models of allergic rhinitis in guinea pigs. Methods12 Hartley guinea pigs (250300?g) were randomly divided into two groups (the control group and the allergen exposure group). Guinea pigs were intranasally sensitized with ovalbumin absorbed on aluminum hydroxide twice a day for 10 days, and after one week they were challenged with 2% ovalbumin solution once every day for a total of 7 times. The negative control group was shamsensitized and shamchallenged by PBS. The symptoms of allergic rhinitis as well as asthma were evaluated. Eosinophils infiltration and pathological changes of the nasal and lung tissues were observed. Levels of IgE and IL5 of the serum were determined by the Elisa method. ResultsIn the allergen exposure group, symptoms of sneezing, nasal scratching, nasal and rhinorrhea were induced after ovalbumin challenge. IgE and IL5 levels increased after challenges. Eosinophil infiltration in the mucosa of the nose and the lungs was more obvious in the allergen exposure group in comparison with the negative control group (P<0.001). Pathological changes were also founded in the nose and lung tissues of the allergen exposure group. ConclusionIt is clear that antigenic stimulation of the upper part of the respiratory mucosa has ripple effects on the lower airway and leads to changes in immunology, which supports the united airway concept.