Abstract: The present invention is a room temperature curable polyurethane composition comprising as a curable component a polyurethane prepolymer having terminal isocyanate groups obtained by reacting an organic polyisocyanate and a polyol comprising as the main component a polyoxyalkylenepolyol having a molecular weight per hydroxyl group of from 1,500 to 15,000 and a total unsaturation degree of at most 0.07 meq/g.The above polyoxyalkylenepolyol having a molecular weight per hydroxyl group of from 1,500 to 15,000 and a total unsaturation degree of at most 0.07 meq/g, is produced by ring-opening addition polymerizing an alkylene oxide to an initiator, preferably by means of a double metal cyanide complex catalyst.By curing this curable polyurethane composition by moisture in air, a highly flexible cured product will be obtained.