Objective　To analyse improvement of pharyngeal cavity spacing and ventilation during perioperative period of combined surgery on palatopharyngeal region and its upper level for obstructive sleep apnea hypopnea syndrome (OSAHS) patients，and explore its clinical significance on  postoperative treatment and screening tracheotomy indication.　Methods  50 OSAHS patients, whose obstruction location were analyzed by apneagraph, nasopharyngeal 3D-computed tomography, electronic nasopharynlaryngoscope，modified uvulopalatopharyngoplasty （UPPP）、endoscopic nasal dilatancy surgery、adenoidectomy,were included in this study. pharyngeal cavity spacing was measured before operation, after general anesthesia、, after operation and in the consecutive three days. Lowest SaO2、average SaO2、 complication were recorded.　Results　After operation, pharyngeal cavity spacing was expanded , and Soft palate length was shortened .In the 12 hours after operation, Lowest SaO2 and average SaO2 increased remarkably. No dyspnea and bleeding were observed, and all patients were exempted of tracheotomy.　Conclusions　Upper airway of OSAHS patients who received UPPP and nasal/nasopharynal combined surgery was widened obviously after operation, with the blockage improved and SaO2 increased accordingly. Acute or chronic obstruction does not appear after three days of operation. Tracheotomy can be avoided when indication and intensive care are under control.