Background Diabetic retinopathy (DR) has emerged as a leading cause of visual impairment and blindness in the working-aged population worldwide.This study aimed to assess frequency and associated factors of progression of DR in subjects with known diabetes in a population-based setting.Methods The Beijing Eye Study is a population based study performed in Greater Beijing in 2001 and 2006.The present investigation included all subjects with known diabetes mellitus in 2001,who participated in the follow-up examination in 2006.Fundus photographs were assessed.Results The study included 170 subjects; 51 (30％) subjects showed signs of DR in 2001 and were re-examined in 2006,36 (21.2％) subjects (18 subjects with DR present at baseline,18 subjects with newly diagnosed DR in 2006)showed a progression of DR during follow-up.Progression of DR was associated with rural region (odds ratio (OR):5.43,P＝0.001) and self-reported arterial hypertension (OR:3.85,P＝0.023).In the non-progressive subgroup,presence of DR was associated with different levels of education (＜middle school,middle school,college or higher,OR:0.30,P＝0.023),treatment modes of diabetes mellitus (OR:10.24,P＝0.003) and cataract surgery (OR:9.14,P＝0.007).Conclusions In a population-based setting in Greater Beijing,progression of DR occurred in 35％ of subjects with pre-existing DR and overall in 21％ of subjects with known diabetes within a 5-year period.Progression of DR was significantly associated with rural region and self-reported arterial hypertension.In the stable subjects,presence of DR was significantly associated with poor educational level,insulin treatment of diabetes and cataract surgery.