OBJECTIVE：To study improvement effect of modified mahuang chanyi decoction on allergic rhinitis（AR）model guinea pigs and its mechanism. METHODS：32 guinea pigs were randomly divided into normal group （0.9％ Sodium chloride injection）， model group（0.9％ Sodium chloride injection），experimental [Modified mahuang chanyi decoction，5.18 g（medicinal materials）/kg] group and control [Fluticasone propionate nasal spray，50 μg/（guinea pig·d）] group. Except for normal group，other groups received ovalbumin 30 mg and calmogastrin 30 mg intraperitoneally to induce AR model. Except for control group，other groups were given relevant medicine intragastrically，twice a day for consecutive 15 d. Nasal symptoms of guinea pigs were observed and recorded，and then analyzed and scored. The protein expression of nasal mucosa SHP-1 was detected by immunohistochemistry， the serum contents of IL-4 and IFN-γ were determined by enzyme-linked immunosorbent assay. RESULTS：Compared with normal group，model group suffered from AR symptom，and nasal symptoms score was increased；and the protein expression of nasal mucosa SHP-1 and the serum content of IL-4 increased，while the content of IFN-γ decreased（P＜0.05）. Compared with model group，AR symptom of experimental group and control group were improved；nasal symptoms score，the protein expression of nasal mucosa SHP-1 and the serum content of IL-4 decreased while the content of IFN-γ increased（P＜0.05）. CONCLUSIONS： Modified mahuang chanyi decoction shows certain improvement effect on AR，and its mechanism is associated the decrease of IL-4 content and the increase of IFN-γ content in serum.