Recently, the incidence of CIS and dysplasia of the uterine cervix is increasing among young women. On that occasion, endocervical conization is often performed as a therapeutic method which can preserve the uterus. However, it may cause cervical stenosis or decrease in cervical mucus and develop sterility. Photodynamic therapy using Excimer Dye Laser which is more penetrative than Argon Dye Laser was applied to the two cases of CIS and four cases of dysplasia of the uterine cervix after basic research on EDL. As a result, photodynamic therapy using EDL could kill cancer and dysplastic cells selectively without damage to the normal cervical glands
