Objective: To explore the clinical factors that affect the recurrence of sinonasal inverted papilloma, and to analyze the predictive value of sinus CT and peripheral blood cells for postoperative recurrence.Methods: A retrospective analysis was made of the clinical data of 38 SNIPs in the Ningbo Medical Center Lihuili Hospital (Eastern hospital compound) from January 2015 to December 2020, with clinical staging performed according to Krouse method. The results of CT staging and actual surgical staging were compared to study the accuracy of CT. At the same time, all cases were divided as recurrence group and non-recurrence group. Peripheral blood neutrophil count, lymphocyte count, neutrophil count/lymphocyte count and sinus CT score were counted, and demographic characteristics and other clinical parameters were compared between the two groups to study the predictive value of related factors of recurrence. Results: The actual coincidence rate of sinus CT in judging the scope of SNIP infringement was 92.11%. Lymphocyte count, NLR and sinus CT score were related to the postoperative recurrence of SNIP, of which NLR and CT score had higher predictive value.(AUC=0.813, 0.929, P<0.01). When NLR=2.375, the sensitivity was 81.8% and the specificity 81.5%; When CT score=5.5, the sensitivity was 81.8% and the specificity 96.3%. Conclusion: The accuracy of nasal sinus CT in judging the scope of SNIP violation is high, with high clinical utility. Lymphocyte count, NLR and sinus CT score are all related factors that affect the postoperative recurrence of SNIP, but NLR and CT score have higher predictive value.