Abstract: Objective: To further improve diagnosis and treatment for chronic fungal rhinosinusitis(CFRS).Method: Forty patients with CFRS were treated with nasal endoscopic surgrey(ESS). The key-points of surgery were as follows: ①for single fungal sphenoid sinusitis, fracturing middle turbinate ourward or resecting one-third of posterior middle turbinate, enlarging the osseous ostium of sinus, removing sinus fungal ball and polypoid nucosa, and flipping mucosa of ostium inside sphenoid sinus to avoid narrow of ostium;②for fungal maxillary sinusitis, retaining uncinate process or resecting tail of uncinate process, enlarging ostium of maxillary sinus according to surgical field, and resecting lesion tissue;③for frontal-ethmoidal sinus lesion, routine treatment was performed; ④iodoform gauze packing the surgical cavity after soaking it with diluted iodine solution(1∶1) for 5 min.Result: Pathological examination indicated that 39 cases were infected with fungus(38 cases with aspergillus and 1 case with mucor, respectively), including 4 cases in which lesion mucosa was invaded by fungus. Of these 39 cases,34 cured after receiving one operation, 4 cases relapsed and finally cured after receiving re-operation or outpatient treatment, 1 case had concomitant sphenoid sinus fibroblastoma with skull base invaded and was remitted after radiation therapy. In addition,1 case was diagnosed clinically as allergic fungal sinusitis although no fungus was found by culture and pathological examination, and the disease was not still controlled completely after several times of recurrence. No complication was observed for all of the cases.Conclusion: ESS is an effective treatment for CFRS, and intraoperative multi-point biopsy may be ignored easily.Confirming whether mucosa of sinus is invaded by fungus as well as pathogenic fungi types will have an important value for postoperative further treatment and reduction of recurrence. Concomitant disease should be considered for the cases with poor curative effect.