Objective To investigate the effects of Atorvastatin calcium on the incidence of macular edema after phacoemulsification in diabetic patients. Methods Forty two eyes of 42 cataract patients with diabetes and hypercholesterolemia who underwent phacoemulsification surgery were divided into interventional group (23 patients) and non-interventional group (19 patients) by random number table methods. The blood glucose and pressure of patients in two groups was controlled strictly before and after surgery. 10 mg Atorvastatin calcium per day was delivered one day after cataract surgery for the patients of interventional group and used for 24 weeks. No lipid-lowing agent was provided to the patients of non-interventional group. The main outcome measures included the best corrected visual acuity (BCVA), central retina thickness (CRT), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C). No significant difference was shown in the BCVA, CRT, TC, LDL-C and HDL-C in two groups before phacoemulsification surgery (t=1.251, 1.257, 1.031, 1.042, 1.461; P > 0.05). At the end of the 24 weeks after surgery, the efficacy evaluation and comparative analysis were performed. The analysis included the BCVA, the incidence of macular edema, CRT, TC, LDL-C and HDL-C. Results The BCVA was no significantly different between two groups one day after surgery (t=1.523，P > 0.05). But 4, 12, 24 weeks after phacoemulsification surgery, the BCVA in interventional group was better than that in non-interventional group(t=3.920, 3.012, 7.025; P < 0.05). 24 weeks after the operation, macular edema was occurred in 2 eyes (8.69%) in interventional group and 4 eyes (21.05%) in non-interventional group. Significance difference was found between two groups (χ2=4.896，P < 0.05). There was no significance different of the CRT between two groups one day after operation (t=1.501，P > 0.05). Whereas, the significance difference of the CRT was occurred in two groups 4, 12, 24 weeks after surgery(t=4.673, 7.583, 9.035; P < 0.05). Comparing with that in non-interventional group, the level of TC (t=7.043, 7.930, 8.611)and LDL-C (t=9.374, 9.554, 10.856) in interventional group was significantly decreased 4 to 24 weeks after operation (P < 0.05). But no significance different of HDL-C was shown in two groups 4, 12 and 24 weeks after surgery (t=1.057, 1.127, 1.295; P > 0.05). Conclusion The treatment of Atorvastatin calcium effectively reduced the incidence rate of macular edema in hypercholesterolemia patients with good glycemic and hypertension control after phacoemulsification surgery.