Objective: To study the pulmonary function and nasal resistance characteristics of patients with chronic nose-sinusitis and nasal polyps (CRSwNP), to explore the evaluation role of nasal resistance in nasal ventilation function and the effect of endoscopic sinus surgery on pulmonary function in patients with CRSwNP., Method: Fifty CRSwNP patients that met the study criteria were selected . The patients were performed endoscopic surgeries according to Messerklinger surgical procedures under general anesthesia. Extent of surgery was based on preoperative CT showing the range of the lesion of disease and endoscopic findings. Perioperative treatments contained intranasal corticosteroids, cephalosporin or penicillin antibiotics, nasal irrigation and other treatments. Main outcome measures included visual analog scale (VAS), endoscopic Lind-Kennedy scores, nasal resistence, pulmonary function in patientsone week before and after surgery, three months and six months after surgery. Pulmonary function includes forced expiratory volume in one second (FEV1), forced vital capacity FEV1/FVC and peak expiratory flow (PEF)., Result: The study found that there were significantly positive correlations among VAS score, Lund-Kennedy score and nasal resistance (P < 0.05) in CRSwNP patients, but there is a significantly negative correlation between VAS score, Lund-Kennedy score, nasal resistance and pulmonary function indexes of FEV1, FVC and PEF (P < 0.05). The VAS score, Lund-Kennedy score and nasal resistance values of CRSwNP patients were decreased significantly after comprehensive treatments with nasal endoscopic operation as the major one, the difference was statistically different (P < 0.05). And the pulmonary function indexs (FEV1, FVC, PEF) were significantly increased after surgery in CRSwNP patients., Conclusion: The nasal resistance can objectively and reliably reflect the degree of nasal congestion and the recovery of nasal function in CRSwNP patients after endoscopic sinus surgery. The detection method of nasal resistance is simple. Functional endoscopic sinus surgery can effectively improve the pulmonary ventilation function in CRSwNP patients, providing some clinical references about the prevention and treatment of CRS related lower respiratory disease.