Phase III Study of Compound Danshen Dripping Pills to Treat Diabetic Retinopathy

Inclusion Criteria: 1. Diagnosed with non-proliferative diabetic retinopathy(NPDR) and TCM syndrome differentiation of qi-stagnation and blood stasis. 2. aged 30-70 years 3. voluntary signs the informed consent One eye met the inclusion criteria can be used as research object, if both eyes met the inclusion criteria, please record respectively, and select one eye for efficacy evaluation with reference to the following principles: When the two eyes of fundus conditions in different clinical stage, choose the more serious one. When the two eyes of fundus conditions in the same clinical stage, choose the eye easier for clinical operation. Exclusion Criteria: 1. HbAlc\>8%, sustained hyperglycemia. 2. The patients who have been received the therapy of Retina laser photocoagulation or diagnosed with proliferative diabetic retinopathy (one or two eyes). 3. Diabetic retinopathy caused by type 1 diabetes mellitus. 4. Combined with glaucoma, uveitis, ocular neuropathy and severe cataract etc. 5. Combined with primarily severe diseases such as cardiovascular, hepatic，renal illness , hemopoietic system disease, and psychosis. Serum transaminase is higher than the limit of normal value of 1.5 times. 6. Diabetic nephropathy with renal failure (Azotemia or Uremia). 7. For women of child-bearing potential: pregnant or lactating or intending to become pregnant. Having any allergic reaction to some drugs. 8. Participated in other clinical trial within 3 months. 9. Used drugs for the treatment of diabetic retinopathy within 1 week. 10. Blood pressure \> 160/100 (systolic above 160 or diastolic above 100).