ATP-sensitive potassium channel(K(ATP)) consists of a 4.4 complex of an inwardly rectifying Kir6.x pore plus a sulfonylurea receptor, which is an ATP-binding cassette transporter. K(ATP) has been indentified in a variety of tissues and recognized as an important drug target. It connects cell metabolism with cell electric activity. K(ATP) has been proposed to play protective roles during heart failure, arrhythmia, myocardial infarction, stress, myocardial ischemia and hypertension. In this review, a summary of K(ATP) is presented with molecular structure, localization, regulation, cardiovascular protective effect and its mechanisms.