Objective To study the effect and mechanism of chlorogenic acid in allergic rhinitis(AR) mice.Methods The model of AR mice was induced by intraperitoneal injection of adjuvant suspension on every other day for 7 times, and then by nasal drip of 10% OVA for 10 days.After administration with 50, 100, 200 mg/kg of chlorogenic acid for 30 min, AR mice were attacked locally for 10 days.Behavior analysis were observed and the effect of chlorogenic acid on the contents of cytokines, IgE and histamine by ELISA in AR mice were determined.Results Chlorogenic acid decreased the number of nose-scratching events in 10min, the weight of nosal draingage, the index of spleen, the content of IL-4 in nasal lavage fluid ( NLF) and the contents of cytokines, IgE and histamine in serum; while increased the index of thymus, the content of IFN-γin NLF, the contents of IFN-γin serum and the rate of IFN-γ/IL-4.The data showed a statistically significant up-regulation of IFN-γmRNA expressions and down-regulation of IL-4 mRNA, IL-5 mRNA, IL-10 mRNA expressions after adiminstration of chlorogenic acid.Conclusion Chlorogenic acid might exert the effect in AR mice through regulating the balance of Th1 and Th2.