An object of the present invention is to provide a curable composition that can be used as sealing materials, adhesives, and the like, has excellent curing properties, and gives a cured product excellent in elongation properties. The object can be attained by means of a curable composition comprising: a reactive silyl group-containing polyether polymer (A) that contains a reactive silyl group with high activity (e.g., (ClCH2)(CH3O)2Si—, (CH3OCH2)(CH3O)2Si—, or CH3(CH3O)2Si—CH2—NH—C(═O)—); and a reactive silyl group-containing polyether polymer (B) that contains a reactive silyl group (e.g., CH3(CH3O)2Si— or (CH3O)3Si—) different from that mentioned above and/or a (meth)acrylic polymer (C) containing a reactive silyl group that is not particularly limited.