Abstract： ·AIM:To compare the outer nuclear layer ( ONL) , inner and outer segments (IS/OS), photoreceptor cell layer in healthy people and diabetic retinopathy by frequency-domain optical coherence tomography ( OCT) .·METHODS: Totally 100 eyes of 50 healthy people were selected as control group. According to conventional mydriasis for examination of fundus and fundus fluorescein angiography ( FFA ) examination, all diabetic cases were divided into 3 groups: normal retina group ( NDR ) , non - proliferative diabetic retinopathy group (NPDR), proliferative diabetic retinopathy group (PDR). Using OCT measure the thickness of ONL, IS/OS and photoreceptor cell layer of fovea and parafovea ( nasal side and temporal side) in the four groups.·RESULTS: Compared with the control group, the ONL and photoreceptor cell layer's thickness of macular fovea and temporal parafovea in NPDR group and PDR group were statistically significant(all P<0. 05). The differences between ONL and photoreceptor cell layer's thickness of macular fovea and temporal parafovea in NDR group and PDR group were not statistically significant(P>0. 05). The IS/OS of macular fovea and temporal parafovea was not significantly different among those groups (P>0. 05). The thickness of different layers of nasal parafovea were not different (P>0. 05).·CONCLUSION: The thickness of macular fovea and temporal parafovea has relation with degree of DR; the change of photoreceptor cell layer's thickness occurs mainly in ONL, but IS/OS no change; the change in temporal parafovea more obvious than in nasal parafovea. Frequency-domain OCT can quantitatively and qualitatively observe the subtle diabetic macular changes in diabetic patients with macular disease, and provides a reliable detection for the early diagnosis and treatment.