Objective：To investigate the significance of serum 25-hydroxyvitamin D3 level in familial type 2 diabetes mellitus （T2DM）with diabetic retinopathy（DR） in Kunming． Methods：Totally 183 T2DM patients with family history of T2DM and DR（DR1 group），79 patients with family history of T2DM and without DR（DR0 group） and 156 healthy individuals（NC group）were enrolled. Clinical data of all subjects including height，weight，blood pressure and other clinical indexes were recorded. Biochemical indexes including blood glucose，blood lipids，HbA1c，insulin-C peptide were examined in three groups. The levels of 25（OH）D3 were mea－sured by ELISA；3 groups were divided based on levels of 25（OH）D3 according to the common criterions and referenced criterions. Percentages of patients in each level of 25（OH）D3 and the difference between the two criterions were compared. Correlation analysis and logistic regression analysis of 25（OH）D3 in DR1 group，as well as multiple stepwise regression analysis of risk factors for DR were conducted． Results：The prevalence of vitamin D insufficiency/deficiency was as high as up to 90% in three groups；the prevalence was higher in DR1 group than in NC group. There was no statistically significance in ratio of the different 25（OH）D3 levels of the com－mon criterions and reference criterions in three groups（P ＞0.05）. Pearson correlation analysis of 25（OH）D3 in DR1 group showed that duration of T2DM，total cholesterol，high density lipoprotein cholesterol（HDL-C），low density lipoprotein cholesterol was positively correlated（r=0.162，0.164，0.189，0.175；P＜0.01），and logistic regression analysis showed that the only variable in the model was HDL-C（r=0.887，P=0.010）. Conclusion：Vitamin D level is generally low in the south population of China. There is no difference between common criterions and reference criterions of different 25（OH）D3 levels in three groups.