Objective To evaluate the effect of intensive insulin treatment on oxidative stress level at early stage of diabetic cardiomyopathy (DCM) in elderly patients. Methods Thirty elderly patients with early stage elderly DCM who received intensive insulin treatment between February 2009 and October 2011 were recruited. Superoxide dismutase(SOD), glutathione peroxidase (GSH-PX) and malondialdehyde(MDA) were measured before and after insulin pump therapy. Results After the treatment, SOD and GSH-PX had more significant improvement[(118.40±25.41) vs (171.16±27.76) U/ml, (120.53±46.26) vs (175.58±52.37) enzyme activity unit; P＜0.01]. MDA significantly decreased [(49.53±14.42) vs (22.65±12.54) nmol/ml, P＜0.01]. Fasting blood glucose [(5.64±0.53) vs (10.96±2.63) mmol/L], 2-hour-postprandial blood glucose [(7.74±1.46) vs (18.50±3.24) mmol/L], insulin resistence calculated according to the HOMA formula [(2.50±1.12) vs (5.90±1.82) mmol/L], total cholesterol [(4.40±0.45) vs (8.44±0.90) mmol/L], tryglyceride [(2.80±1.01) vs (6.84±1.83) mmol/L], low-density lipoprotein cholesterol [(3.01±0.73) vs (5.11±1.35) mmol/L], and free fatty acid [(0.34±0.11) vs (0.73±0.10) mmol/L] all decreased significantly (P＜0.05). Homa-b increased significantly [(73.32±12.20) vs (11.8±5.50) mmol/L, P＜0.05]. Cardiac diastolic function was significantly improved [(0.74±0.35) vs (1.09±0.23), P＜0.01]. Conclusions After subcutaneous insulin injection treatment, oxidative stress level significantly decreases and cardiac diastolic function significantly improves in elderly patients with early stage DCM.