【Abstract】 Angiotensin converting enzyme（ACE，Kininase II），which is secreted by pulmonary and renal endothelial cells，participates in the body's renin-angiotensin system (RAS). Which primarily catalyzes the conversion of angiotensin I to octapeptide angiotensin II（a potent vasoconstrictor）, mediates extracellular volume and arterial vasoconstriction. Studies showed that excessive or diminished ACE plays an important role in some lung disease, such as sarcoidosis, lung cancer, COPD, acute lung injury and so on. The goal of this review is to summarized the relevant studies about ACE in lung injury. 【Key words】Angiotensin converting enzyme；lung injury