목적: There were several researches about Nasal polyposis (NP). The aim of the study is to evaluate the patterns and characteristics of patients who diagnosed chronic rhino sinusitis (CRS) with diffuse nasal polyposis. 방법:A total 104 patients who were diagnosed CRS c polyp or CRS s polyp and underwent the surgical treatment in Kyunghee Medical Center from July 1, 2014 to December 31 2014 were enrolled. For all patients the diagnosis of diffuse nasal polyposis was based on the following criteria the visualization of bilateral polyps in the nasal cavities on endoscopic examination and the existence on CT of bilateral opaque areas located in the ethmoid sinuses, whether in the anterior and the posterior ethmoid portion. We defined a group that meets the above criteria with severe polyposis patient group. The data consist of comorbid diseases(allergic rhinitis, asthma, previous ESS history, etc), Lund-Mackay CT scoring, endoscopic polyp staging, TNSS, SNOT-20, aspirin provocation test, eosinophil count and IgE. 결과:A total 104 patients were divided two groups. 31 patients were suitable for the criteria defined to diffuse polyposis. According to the data, in the comorbid disease, aspirin provocation test, there were no significantly differences between two groups. In TNSS and SNOT, severe polyp group had higher average scores than others, but, there were no significantly differences. However, there were differences statistically significant in Lund-Mackay CT scoring (P = 0.048) and endoscopic polyp staging (P = 0.00). In olfaction test (KVSS), especially threshold, recognition test and KVSS total score, there were statistically different between the two groups (P = 0.013, P = 0.00). 결론:In this study, many diffuse nasal polyposis patients have olfactory problems especially. Therefore, studies about correlation between severity of nasal polyposis and olfaction function should be more considered. And, the olfaction function after treatment related to nasal polyp should be followed.