·AIM:To investigate the value of optic disc formation analysis in early diagnosis of primary open angle glaucoma.·METHODS:Seventy-two examinees whose cup-disc ratio were 0.5-0.8 underwent ophthalmic routine examina-tions,gonioscopy,perimetry and optical coherence tomography(OCT),and the results were analyzed.·RESULTS:The intraocular pressure of only 10 exami-nees with normal optic disc formation fell on the "suspicious" range.All the examinees with normal optic disc formation got normal results in perimetry and OCT.A big proportion of examinees with abnormal optic disc formation got abnormal results in intraocular pressure measurement,perimetry and OCT.·CONCLUSION:The optic disc formation is a sensitive factor in early diagnosis of primary open angle glaucoma.·