·AIM:To investigate the changes of homocysteine(Hcy),cystatin C and high-sensitivity C-reactive protein(hs-CRP)in patients with type 2 diabetic retinopathy(DR)and determine if any correlations exist among these factors.·METHODS:Patients with type 2 diabetes mellitus(DM)without DR group included 45 individuals.Type 2 DM with nonproliferative DR group consisted of 42 patients and type 2 DM with proliferative DR group was composed of 46 patients.The control group comprised 40 healthy human beings.ELISA was utilized to assay the contents of Hcy and cystatin C while hs-CRP was detected by immune turbidimetry.Linear correlation analysis was used in bivariate correlation analysis.·RESULTS:The contents of Hcy,cystatin C and hs-CRP of patients from the 3 groups were significantly higher than of those from the control group(P<0.01).There were significant differences among all the groups(P<0.01).And the contents of the three factors increased significantly with the severity of disease(P<0.01).Hcy and cystatin C contents showed an increasing trend,and positive correlation between the two factors was observed(patients with type 2 DM without DR group:r=0.675;type 2 DM with nonproliferative DR group:r=0.823;type 2 DM with proliferative DR group:r=0.756,P<0.01).·CONCLUSION:The blood plasma contents of Hcy,cystatin C and hs-CRP in patients with type 2 DR are far higher than control,which suggests that detecting of the three factors possesses clinical significance for early diagnosis and therapy in type 2 DR.Associated assay may contribute to speculate the disease severity and therefore get an all-around judgment.Our study provides theoretical basis to the clinical intervention of blood Hcy,cystatin C.·