〔Abstract〕 Objective To explore the expression and clinical significance of interleukin-19(IL-19) in different types of chronic rhinosinusitis with nasal polyps(CRSwNP). Methods 42 CRSwNP patients were selected to collect nasal polyps during the operation: 20 patients with eosinophilic chronic rhinosinusitis with nasal polyps(ECRS), 22 patients with non-eosinophilic chronic rhinosinusitis with nasal polyps(non-ECRS). 20 patients in the control group were selected to collect mucosa of uncinate process during the operation. The percentage of eosinophils in tissues was measured by hematoxylin-eosin staining, and the expression of IL-19 was measured by qRT-PCR and immunohistochemistry staining. Results IL-19 was mainly expressed in epithelial and submucosal glands of polyps in ECRS. The mRNA and protein expression of IL-19 was significantly higher in ECRS than in non-ECRS,and higher than in control(P<0.05,P<0.05). In ECRS group, the mRNA level of IL-19 was positively correlated with CT Score, endoscopic score and percentage of eosinophils(P<0.05,P<0.05,P<0.05), but not with VAS score(P>0.05). Conclusion Compared with non-ECRS and normal nasal mucosa, the expression of IL-19 in ECRS is higher, and is positively correlated with clinical severity. IL-19 may aggravate clinical symptoms by promoting the aggregation of eosinophils.