The adenomatoid odontogenic tumor(AOT) is a benign tumor of odontogenic epithelium characterized by slow but progressive growth and rare recurrence. Tumor growth may cause displacement of teeth rather than root resorption. The AOT appears in 3 clinicotopographic variants such as follicular, extrafollicular, and peripheral. The follicular AOT mimics a dentigerous or follicular cyst and the extrafollicular cyst does a residual cyst, globulo-maxillary cyst and lateral periodontal cyst. Although over 750 cases of AOT were reported in the literature, clinicopathologic parameters of AOT in Koreans has not been investigated. 22 cases of AOT were retrieved from the files of the department of Oral Pathology, Seoul National University Dental Hospital and their clinicopathologic findings were reviewed. The central type accounts for 95%, 72% of which are follicular. The follicular and extrafollicular varients together are more commonly found in the maxilla than in the mandible with a ratio of 4.5:1. Age distribution showed that 59% of AOTs were diagnosed in the second decade of life, and mean age was 18.5 years. The female to male ratio was 3.4:1. All variants of AOT showed identical histologic features.