Objective To investigate the safe and effective dosage of enoxaparin in the elderly patients with coronary heart disease and renal insufficiency during interventional operation. Methods A total of 108 senile patients with above 2 disorders who received interventional treatment and perioperative enoxaparin for anticoagulation in our department from January 2009 to December 2012 were recruited in this study. They were divided into 3 groups according to the dose of enoxaparin, that is, group A (n＝31, 40mg enoxaparin, subcutaneous injection, once every 12 hour), group B (n＝35, 40mg enoxaparin, subcutaneous injection , once a day), and group C (n＝42, 40mg enoxaparin, subcutaneous injection, once every morning, and 20mg once every night). They all took the same doses of aspirin and clopidogrel. The bleeding and stent thrombosis rate were observed and compared among the 3 groups. Results No massive hemorrhage or stent thrombosis was found in the 3 groups. But the patients from group A had significantly higher prevalence of subcutaneous hemorrhage and gum bleeding than those from the other 2 groups. Conclusion It is quite safe and effective for the elderly coronary heart disease patients accompanied with renal insufficiency to be given 40mg enoxaparin, subcutaneous injection, once every morning, and 20mg once every night, for a total of 5 to 7d during interventional therapy.