Squamous papilloma is a benign proliferation of stratified squamous epithelium, resulting in a papillary or verruciform mass. Verrucous carcinoma is a differentiated variant of squamous cell carcinoma and may present diagnostic difficulties as it may be erroneously diagnosed as squamous papilloma. Squamous papilloma is similar to other oral mucosa malignancy in microscopic view. So, it is difficult to distinguish between squamous cell papilloma and other oral mucosa malignancy. Here are three patients. they were diagnosed as squamous papilloma initially, but the lesion was recurred. In recurred lesion, verrucous carcinoma or squamous cell carcinoma were found. So we report that recurred oral mucosa malignency(verrucous carcinoma or squamous cell carcinoma) which was diagnosed as squamous papilloma.