Chronic rhinosinusitis with nasal polyps (CRSwNP) is a multifactorial disease. The pathogenesis of CRSwNP remains unclear. This study was designed to investigate the role of inflammation and Staphylococcus aureus enterotoxin (SE) in this disease. The study included a total of 74 patients with CRSwNP and 6 controls. A serum Phadiatop assay was conducted to detect atopy status, and serum eosinophil cationic protein (ECP) and total immunoglobulin (Ig)E levels were determined using ELISA. SEA, SEB, total IgE, ECP and myeloperoxidase (MPO) levels in nasal tissue supernatant were measured using ELISA. The results indicated that 15 (22.1%) patients had systemic allergies. On the basis of the ECP/MPO ratio, the patients were divided into an eosinophilic CRSwNP group (n=18) and a non-eosinophilic CRSwNP group (n=56). The total ECP/MPO ratio was 0.572, with a notable bias toward neutrophilic inflammation. The supernatant ECP and MPO levels were elevated in the CRSwNP group compared with the control group, but no significant difference in the serum total IgE and ECP levels were observed between the CRSwNP and control groups. In addition, the non-eosinophilic and eosinophilic CRSwNP groups showed significant elevations in supernatant total IgE, SEA and SEB levels compared with the control group. Thus, it may be concluded that allergy is a common pathogenesis of CRSwNP, and neutrophilic inflammation is present in most Chinese CRSwNP patients. Additionally, local indicators reflect the inflammatory status more accurately than do serum indicators. SEs may act as an infection factor rather than as a superantigen in Chinese non-eosinophilic CRSwNP patients. Thus, long-term antibiotic therapy may be an option for Chinese non-eosinophilic CRSwNP patients.