Between June 1990 and May 1994, 350 laser conization and 200 LEEP were performed. Indications of conization were that directed biopsy specimen was proved CIN II, III or suggests possible microinvasion. In all the cases the procedures were carried out with the patients under local anesthesia. Excisional cone sections(6,600) were evaluated for lesion length,depth and margin status. Invasive cancer was found in 5(1.4%) women of laser group. Operative time was shorter LEEP group than laser group significantly. In laser group, 25(8.3%) women had bleeding that required treatment. One case(0.3%) of pelvic infection and 7 cases(2.3%) of cervical stenosis were observed. In LEEP group, 10(5.3%) women had bleeding, 3(1.6%) patients became cervical stenosis. The diameter of bumed tissue was 0.28mm in laser group and 0.25mm in LEEP group. Success rate were 97.4% in former and 96.3% in later. This study demontrated that CO2 laser conization and LEEP were effective methods for treating high grade cervical intraepithelial neoplasia and added benefit of preserving reproductive function and rule out invasive carcinoma.