There have been many different histological typing of odontogenic tumours and numerous reports on the epidemiological studies of the odontogenic tumours depending upon various these histological typing. Neoplasms and other tumours related to the odontogenic apparatus was classified into 21 entities by WHO in 1992. The purpose of this study is to get the clinically basic data of the odontogenic tumours in Korean according to this newly made WHO histological classification. The total of 4913 biopsied specimens were reviewed from the dept of Oral Pathology, College of Dentistry, Yonsei University for the period of Jan. 1985. to Dec. 1996. and among them 156 cases were diagnosed into the odontogenic tumours. The following results were obtained: 1. Odontogenic tumours were 156 cases(3.18%) of the total 4913 biopsy cases. Only the 10 different benign entities were observed in 156 cases of odontogenic tumour. 2. The most frequent odontogenic tumour was ameloblastoma(42.3%) and followed odontomas (41.0%), adenomatoid odontogenic tumours (4.5 per cent) and ossifying fibroma(3.8%) in order. 3. Overall male to female ratio was 1.14(53.2%) to 1(46.8%), but female ratio is higher than male in odontoma(53.1%) and myxoma(75.0%) respectively. 4. 134 cases(85.9%) of all odontogenic tumours were observed under the age of forty. Age distribution showed 60 cases(38.5%) in the second decade, 37 cases(23.7%) in the third decade, 22 cases(14%) in the fourth decade and 15 cases(9.6%) in the first decade of life 5. The ratio of odontogenic tumours of the mandible to maxilla was about 2 : 1 . Odontogenic tumours occured predominantly in the molar region(29.6%) and gonial region(17.08%) of the mandible and anterior region(18.8%) of the maxilla. Ameloblastoma occurred mostly in the molar region(45.5%), gonial region(28.1%), ascending ramus region(10.7%) and premolar region(9.1%) of the mandible, while odontomas predominated in the anterior region(44.9%) of the maxilla. 6. Most ameloblastomas were related with more the impacted teeth(62.1%) and root resorption(53.0%) than teeth migration(27.3%). In case of odontoma, teeth impaction(62.5%), teeth migration(75.0%) and root resorption(7.8%) were observed. 7. In the ameloblastomas, facial swelling was the most frequent chief complaint(80.3%) and followed by pain(9.1%).