As economical and social status are getting better, many ordinary people are interested in well being and leisure sports, the populations enjoying SCUBA diving are increasing recently. The medical problems from SCUBA diving are also increasing. To provide diving knowledge to the medical Drs. for prevention of barotrauma from SCUBA diving and to provide medical knowledge to SCUBA divers for safer diving, author reviews barotrauma of the human body from SCUBA diving. Review includes diving physics, mechanism, clinical manifestations and prevention of barotrama. Pulmonary barotrauma manifests as pulmonary tissue damage, pneumothorax, mediastinal emphysema with or without arterial gas embolism. Arterial gas embolism is one of the most serious and urgent medical problem from SCUBA diving and it need immediate recompression treatment. Barotrauma in the middle ear is the most common medical problem from SCUBA diving, it manifests as Eustachian tube salpingitis, otitis media with effusion. Inner ear barotrauma may lead permanent sensorineural hearing loss. Barotruma also can be occurred in mask,1)teeth, dry suit, and gastrointestinal tract. Prevention of barotrauma is more important than treatment. Prevention of barotrauma is up to divers, diving instructors and medical Drs. Divers and diving instructors should follow guidelines in diving fitness test, keep physical state always to fit to dive, keep diving skills as sharp and keep physical ability to adjust changeable ocean environment. Medical Drs. are responsible to their decision of medical fitness test, so they should know about diving physic, diving physiology and recent guidelines about medical fitness to dive.