Odontogenic tumours and tumour-like lesions are relatively rare in oral and maxillofacial region. Most of them are benign and develop and grow slowly inside of the jaw without pain. Since the clincal course, behaviors and histopathological features of them have many points of resemblance to each other, there are considerable diagnostic difficulty both for the clinician and pathologist. And recognition and understanding about histogenesis of the tooth may be necessary for appropriate diagnosis of these lesions. Many attempts have been made to classify the tumours and tumour-like lesion of the odontogenic tissues. In 1992, the new classificaton of the odontogenic tumours, entitled “Histological Typing of Odontogenic Tumours”, were published by WHO. This classification is based on clinical behavior of the tumours and histologically embryonal inductive principles and elements of the odontogenic tissues in the tumours. According to this classification, incidence, clinical behavior and histopathological characteristics of the odontogenic tumours were presented with typical clinical cases of ameloblastoma and odontoma. As to relatively rare cases of odontogenic tumour, adenomatod odontogenic tumour, calcifying odontogenic cyst and odontogenic fibroma and other several cases were presented. Also treatment of odontgenic tumour were discussed with reference to conservative surgical method.