Inverted papilloma arising from mucous membrane of the nasal cavity and paranasal sinuses is an uncommon benign neoplasm. It has a tendency to recur frequently after removal and occasionally change into malignancy with extensive bone erosion. Thus, this tumor was histologically benign neoplasm and clinically malignant. Recently, authors have experienced a case of invasive squamous cell carcinoma changed from inverted papilloma during 2 years in the(Lt.) nasal cavity and maxillary sinuses. Inverted papilloma was removed surgically through intranasal approach. About 2 years late, tumor mass recurred and rebiopsy report revealed invasive squamous cell carcinoma, which was removed through lateral rhinotomy and Caldwell-Luc's approach and then was treated with systemic administration of Bleomycin, Cis-platinum. We report our case with review of current literature.