PURPOSE: To provide a morphine-containing suppository having a high biological availability through recta and persisting an effective concentration of the ingredient in blood by compounding the morphine, α-cyclodextrin and a thickening agent.

CONSTITUTION: Morphine, α-cyclodextrin, and a thickening agent such as xanthane gum, locust bean gum, arabinogalactan, β-1,3-glucan or hydroxypropyl cellulose are mixed each other and subsequently filled into a hollow sappository to provide the intrarectal administration drug remarkably improved in the biological availability and concentration persistence of the ingredient in blood. Morphine hydrochloride, morphine sulfate, etc., are preferably as the morphine. A weight ratio of the morphine to the α-cyclodextrin is preferably 1:5-1:100, and a weight ratio of the morphine to the thickening agent is preferably 1:5-1:100.