Objective: Olfactory impairment is commonly observed in chronic rhinosinusitis with nasal polyps(CRSwNP) and has a significant impact on quality of life. However, the risk factors for olfactory impairment have not been fully understood, and whether atopy is predisposed to olfactory impairment in CRSwNP patients remains unclear. The present study aims to unveil differences in olfaction and sinonasal symptoms between CRSwNP with and without atopy by means of a hospital-based, cross-sectional survey. Method: In this study, 288 CRSwNP patients ready for sinus surgery were consecutively enrolled, and atopy, olfaction, sinonasal symptoms and CT scores were evaluated. Result: We found 71.3% of CRSwNP patients presented olfactory loss and 34.5% of them presented olfactory complaint in this cohort (In this study, olfactory impairment has been defined when VAS≥1 and olfactory dysfunction has been defined when VAS≥5).The decreased olfactory function was associated with sinonasal symptoms(nasal congestion and rhino rhea) and total CT scores (P<0.01), but not with atopy. Multivariate logistic regression revealed that nasal congestion score and total CT score were risk factors for olfactory dysfunction (OR, 1.293 and 1.349; P<0.01) in CRSwNP patients. Conclusion: Our findings indicate atopic condition may not directly cause olfactory impairment, and physician should pay attention to the surgical treatment for local disease severity to improve the olfactory function and quality of life..