Previous studies have demonstrated that the eosinophilic inflammation of nasal mucosa is associated with the uncontrolled condition of chronic rhinosinusitis after surgery. However, the definition of the eosinophilic chronic rhinosinusitis is not very clear. Japanese researchers have designed a scoring system to diagnose eosinophilic chronic rhinosinusitis. In this study, the investigators hope to examine the practicability of this scoring system and have a better knowledge of eosinophilic chronic rhinosinusitis in china.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.