PROBLEM TO BE SOLVED: To provide a curable composition useful as a sealant or an adhesive having excellent restoring properties, heat resistance and follow-up properties to movement of a joint over a long period and properties of following to an adherend and bonding thereto. SOLUTION: The curable composition comprises a polyoxyalkylene polymer (A). Furthermore, the polyoxyalkylene polymer (A) has 16,500-50,000 number-average molecular weight and contains a group represented by general formula (1) -(SiR 1 2 O) n SiR 1 2 -R 2 -SiX 3 (wherein, R 1 represents a monovalent hydrocarbon group and 2n+2 R 1 s may mutually be the same or different; R 2 represents a 1-20C bivalent hydrocarbon group; X represents a hydroxy group or a hydrolyzable group and 3 Xs may mutually be the same or different; and n represents an integer of 0-100) as a silicon-containing group cross-linkable by forming a siloxane bond. COPYRIGHT: (C)2007,JPO&INPIT