<p>A curable composition. The composition contains (A) 100 parts of an oxyalkylene polymer having at least one silicon-containing group containing a hydroxyl group and/or hydrolyzable group bound to a silicon atom and capable of crosslinking through the formation of a siloxane bond; (B) 1 to 150 parts of a high molecular weight and/or high viscosity plasticizer; and (c) 0.1 to 20 parts of a compound having one silanol group per molecule and/or a compound capable of reacting with moisture to thereby form one silanol group per molecule. When an alkyd paint is applied onto the surface of a cured material formed from this curable composition excellent coating properties can be obtained, the other physical characteristics of the cured material being maintained. r</p>