It is very difficult to differentiate the malignant tumor from the maxillofacial infections that have unclear cause, severe indurated swelling, pain and nonresponsiveness to antibioitic treatment and incision and drainage. Incisional biopsy, CT, and MRI examination may not distinguish between infection and a malignant tumors. And then, the clinicians can make a mistake that they perform a unnecessary radical surgery because of inaccurate diagnosis. We present three case reports of maxillofacial infectious disease with diagnosis process, treatment and differential diagnosis. The infectious disease were not resolved with antibiotic and surgical drainage. The progression of clinical sign and radiographic, indings of these disease were masqueraded as malignant tumors.