Creatine kinase MB is generally referred to as creatine kinase isoenzyme MB and is an important indicator for the diagnosis of acute myocardial infarction. Creatine kinase is an important indicator of laboratory tests, and the creatine kinase molecule is mainly a dimer composed of brain-type subunits and muscle-type subunits. Usually the normal human body contains three isoenzymes, namely CK-BB, CK-MB and CK-MM, among which, CK-MB is mainly found in myocardial tissues, and if CK-MB is released into the blood, it can be called an important indicator for diagnosing acute myocardial infarction. Generally the normal reference value of CK-MB is <0.6ng/ml, if CK-MB is proliferated in serum, it is mostly seen in trauma, strenuous exercise, acute myocardial infarction, skeletal muscle injury, rhabdomyosarcoma and so on. And patients who undergo cardiac surgery that damages the myocardium may also experience a transient elevation of CK-MB. Most often it recovers within 24 hours after surgery. It is recommended that patients with abnormal creatine kinase isoenzyme MB should promptly identify the cause of the disease and take reasonable treatment.