To provide a curable composition, which can be made into one-pack type to be cured by reacting with moisture in the air at room temperature and gives a cured product having an excellent strength, elongation at break, weatherability and adhesiveness.

The cured product comprises 100 pts.wt. of a vinyl-based polymer (I) having at least one crosslinkable silyl group with a main chain prepared by living radical polymerization and 1-200 pts.wt. of a hydrophobic impalpable powder of silica (II). Also, the cured composition comprises 100 pts.wt. of a vinyl-based polymer (I) having at least one crosslinkable silyl group with a main chain prepared by living radical polymerization and 1-200 pts.wt. of a graft copolymer (III) prepared by graft-polymerizing a vinyl monomer onto an acrylic acid ester-based crosslinked rubbery polymer.