The eosinophil is a characteristic cell in the IgE mediated allergic reaction, containing granule proteins, such as ECP and MBP, which are cytotoxic to helminths and epithelial cells in the airways. The eosinophil can be classified into storage form of EG1(+) cells and secreted form of EG2(+) cells. In this study, we performed measurements of EG1(+) cells ; storage form and EG2(+) cells ; are secreted form in nasal mucosa of perennial allergic rhinitis, and studied the effect of steroid nasal spray. Staining of EG1 and EG2(+) cells of 36 patients with perennial allergic rhinitis, 20 patients treated with steroid nasal spray, and 20 normal control group was performed with monoclonal antibody EG1, EG2 and LSAB kit. We analyzed the correlation between the number of EG1(+) and EG2(+) cells with nasal symptoms. The number of EG1(+) cells were 175.5±165.1/HPF in untreated group, 59.2±50.3/HPF in treated group, and 12.1±10.4/HPF in normal control group respectively. The number of EG2(+) cells were 52.3±49.2/HPF in untreated group, 6.8±6.2/HPF in treated group, and 1.6±3.3/HPF in normal control group respectively. The numbers of EG1 and EG2(+) cells of untreated group were increased significantly than those of untreated and normal control group, and there were significant correlations between the number of EG2(+) cells with nasal symptoms in untreated patients group. In conclusion, we have demonstrated the possibility of participation of eosinophils in the pathophysiology of perennial allergic rhinitis and action of eosinophil that can be modulated by steroid nasal spray.