Objective To ummarized the clinical characteristics of lactic acidosis combined with hypoglycemic coma,diabetic ketoacidosis and hyperkalemia,so to improve the physician's treatment ability by summary the clinical feature of lactic acidosis combined with hypoglycemic coma,diabetic ketosis and hyperkalemia.Methods Analyzed the clinical characteristics and disease development of one case with lactic acidosis combined with hypoglycemic coma,diabetic ketoacidosis and hyperkalemia,and reviewed literature.Results The patient had hypoglycemia and acidosis at the same time due to taking phenformin and glibenclamide.After 2 days,the patient was better through correcting acidosis,intravenous fluid therapy,lowering blood potassium and controlling blood glucose.Conclusion Because acidosis caused the potassium transfer from intracellular to extracellular,the latter leads to hyperpotassemia,lactic acidosis caused by phenformin should be treated with intravenous fluid therapy,correcting acidosis.