The retrospective study was conducted in a tertiary hospital. Participants received functional endoscopic sinus surgery more than 1 years were called back for evaluation. A diagnosis cut off value of eosinophil count was determined by the surgery prognosis. Then different factors were compared between participants with eosinophilic CRS and those with non-eosinophilic CRS to establish the appropriated diagnosis approach for eosinophilic CRS.