Objective To investigate the electrocardiogram and clinical data of people taking cough syrup or addicted to heroin. Methods A total of 450 people took cough syrup or addicted to heroin who were treated in the addiction medicine department of our hospital were collected from December 2007 to December 2011 and divided into two groups according to the addition type, with 200 cases in the cough syrup group and 250 cases in the heron group, and the con-trol group consists of 200 normal healthy persons. The patients' fasting glucose, total cholesterol, serum triglycerides, blood low-density lipoprotein cholesterol, blood high-density lipoprotein cholesterol, blood pressure and electrocardio-gram were recorded. Results The cough syrup group compared with the heroin group, the control group had higher hemoglobin, total cholesterol, triglycerides, systolic blood pressure, diastolic blood pressure, high-density lipoprotein cholesterol and low density lipoprotein cholesterol, with statistically significant differences (P<0.05); Compared with the cough syrup group, the heroin group had lower hemoglobin, total cholesterol, triglycerides, systolic blood pressure, diastolic blood pressure, high-density lipoprotein cholesterol and low density lipoprotein cholesterol, with statistically significant differences (P<0.05); The control group had the lowest incidences of bradycardia, sinus tachycardia, prema-ture atrial contraction, premature ventricular contraction, left anterior branch conduction block, left posterior branch conduction block, atrioventricular conduction block, ST-T change, limb leads low voltage, QT interval prolongation change, complete right bundle branch block and incomplete right bundle branch block, and the heroin group had the highest incidences, with statistically significant differences (P<0.05). Conclusion Of the 3 groups, the heroin group has the severest myocardial and biochemical damage and the cough syrup group also has varying degrees of damage. Anti-drug publicity should be strengthened in order to improve the awareness of drug harm.