Objective To analyze the difference of macular retinal thickness between normal subjects and diabetic patients without retinopathy,and discuss the relationship between macular thickness and the course of diabetes,blood glucose level.Methods Twenty-two cases of patients with diabetic without retinopathy without retinopathy in our hospital of fourth Department of Internal medicine from April 2016 to November 2016 were selected as diabetic without retinopathy group,and another 22 normal pemons were selected as the normal group.The central subfield retinal thickness (CSRT),cube volume(CV) and cube average thickness(CAT) of all patients were determined by optical coherence tomography (OCT),and the difference of CSRT,CV and CAT between diabetic patients and normal group were analyzed.Then,the patients with diabetic retinopathy were sub-grouped according to the course of diabetes (group A,B,C,) and blood glucose status (group D and E),and the differences of CSRT,CV and CAT among them were compared.Results With the increase of diabetes duration in the diabetic without retinopathy group,CSRT,CV and CAT were gradually increased,and there was significant difference (P ＜ 0.05).With rising blood sugar in diabetics in the diabetic without retinopathy group,CSRT,CV and CAT were gradually increased,and there was significant difference (P ＜ 0.05).There were positive correlation between CSRT,CV,CAT and course,blood sugar of diabetes mellitus (all P ＜ 0.05).Conclusion Compared with normal population,CSRT,CV and CAT are significantly thickened in diabetes mellitus patients,and CSRT,CV and CAT are increased gradually with the increase of diabetes and blood glucose,which provide reliable reference for the diagnosis of early diabetic retinopathy.