Objective: To analyze the role of instruction of drug administration for the safety of drug taking in senile diabetes mellitus patients.Methods: Eighty four patients with diabetes were divided randomly into study group and control group.Patients in study group were educated systematically with associated knowledge of diabetes and drug medications;patients in control group were instructed simply with routine knowledge of drug taking.Results: Patients in study group knew far more about the administration of drug than those in control group;complications associated with unsuitable use of the drugs after discharge in the patients of control group were obviously higher than those in study group according to the results of follow-up.Conclusion: To educate patients with systematic standard knowledge of drug medication may enable them command more knowledge and information of safety of drug usage,may assure the therapeutic effect and safety of drug administration.