Objective : To evaluate the role of antioxidant on CIN I by colposcopy and biochemical examination of plasma levels of enzymes. Material and Methods : Study was conducted i department of Obs and Gynae of G.S.V.M. Medical College, Kanpur. 230 patients attending OPD with suspected cervical lesion were screened by PAP smear, colposcopy and confirmation of diagnosis made by HPE. 180 patients were subjected to histopathology out of which 60 patients of CIN I were taken in this study. Of all 60 patients biochemical examination was done for plasma levels of malonyldialdehyde as marker of lipid peroxidation and superoxide dismutase and catalse.