Misoprostol is a derivative of prostaglandin E, which has the effect of softening the cervix and enhancing uterine tone and intrauterine pressure. In combination with mifepristone sequentially, it significantly increases or induces the frequency and amplitude of spontaneous uterine contractions and is mainly used for termination of intrauterine pregnancy up to 16 weeks, postpartum hemorrhage, and treatment of incomplete abortion. It can also be used as a first-line drug for the treatment of postpartum hemorrhage due to lack of uterine contractions in the absence of contraction, and is applied as misoprostol tablets 200-600 mcg administered either tonically or sublingually. This drug may also promote the healing of peptic ulcers or relieve their symptoms. The protective effect on the gastric and duodenal mucosa is achieved by inhibiting basal, irritant and nocturnal gastric acid secretion, reducing gastric acid secretion, decreasing gastric juice secretion, decreasing protein hydrolase activity of gastric juice, and increasing bicarbonate and mucus secretion, thus enabling the treatment of duodenal ulcers, gastric ulcers (including those caused by taking NSAIDs) and the prevention of NSAID-induced ulcers. This drug does not require dose adjustment in the elderly and in patients with renal insufficiency.