The technique of large loop excision of the transformation zone(LLETZ) as an alternative to destructive/ablative methods of treatment of CIN(cervical intraepihelial neoplasia) such as cryotherapy, laser vaporization and cone biopsy was assessed. In 63 women with suspected CIN attending the colposcopy clinic, the histologic diagnoses made from excision biopsies taken by LLETZ were compaired with those from colposcopically directed punch biopsies. This microinvasive tumors were found by LLETZ and the diagnosis made by LLETZ was worse than that made by punch biopsy in 17 cases(26.9%). That is to say, LLETZ improves the accuracy of diagnosis of CIN. And in offers a cheap and accurate alternative to laser vaporization or cone biopsy, and also combines the benifits of the gold standard cone biopsy with that of local ablative metholds. LLETZ is considered as a fairly new and good method of treatment of CIN, and the olng-term complications or effects should by yet fully evaluated in future.