The carcinoma of uterine cervix is the most common malignant neoplasm in Korean women. Nearly all invasive cervical carcinomas are preceded by a intraepithelial stage. The cervical intraepithelial lesion(CIN) is subdivided into I, II, and III, depending on the severity of the changes. To evaluate the histologic characteristics of the CIN, we studied the CIN III by mapping of the uterine cervix. The results were as follows. 1. The CIN III without I or II was 54.8%(17/31 cases). 2. The multifocal CIN III was 12.9%(4/31 cases). 3. The horizontal growth of CIN III was 38.7%(12/31 cases). These results indicate that the CIN III is unifocal and CIN III without I or II is more common.