Premature cardiac contractions are a type of arrhythmia in which an ectopic pacing site outside the sinoatrial node generates an early excitation that causes the heart to beat, and according to the location of the ectopic pacing site, they can be categorized as atrial, junctional, and ventricular premature contractions. Atrial premature beats, also known as atrial pre-systole, are caused by an early excitation of an ectopic pacing site located in the atria, and are mostly functional and do not require special treatment. Atrial premature beats can be detected in 60% of normal people with 24-hour ambulatory electrocardiogram (ECG) monitoring. Junctional premature beats, also known as junctional pre-systole, have an ectopic pacing site in the atrioventricular (AV) junction area and do not require treatment in most patients. Premature beats with an ectopic pacing site in the ventricle are called ventricular premature beats or ventricular pre-systoles, and can be functional or caused by certain organic heart diseases, such as acute myocardial infarction. The former can be alleviated by eliminating the triggering factors, such as avoiding mental stimulation, reducing coffee intake, and quitting smoking. The latter is mainly for the treatment of the primary disease, such as acute myocardial infarction patients should be restored as soon as possible to restore myocardial blood perfusion, and some of the symptoms of the obvious need to apply amiodarone, verapamil, metoprolol and other anti-arrhythmic drugs. Patients with premature beats are advised to go to the hospital as soon as possible to have a professional doctor assess the severity of their condition and formulate a scientific treatment.