Two hundreds and ten patients with abnormal cervical smears were found in our-Gynecological Department from 1975 to 1979. By colposcopically directed biopsies

93 cases were diagnosed as severe

dysplasia(12cases)

carcinoma in-situ(70cases)and early invasive carcinoma(llcases). The results of colposcopically directed biopsies were correlated with the pathological diagnosis of endocervical currettage

hysterectomy and cone biopsy specimens. The diagnostic accuracy of colposcopically .directd biopsies were 90.3 % and that of colposcopically directed biopsies plus endocervical currettage were 96.8%.Our study showed that the greater the surface area of atypical transformation zone

the greater the possibility of invasive carcinoma. In all cases of severe dyspla-sia and carcinoma in-situ

with the entire atypical transformaion zone visualized during examination

except one

the surface area of atypical transformation zone was seen within of the cervical surface. The indications of diagnostic conization of cervix were discussed.