TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The organic polymer (I) is a polyoxyalkylene polymer that contains 5-80 wt.% of oxyethylene units. The organic polymer (I) is produced: from a compound containing active hydrogen as a starting material; and by converting the active hydrogen of the starting material into a hydrolyzable silyl group. The number average molecular weight of the organic polymer (I) is 500-15000. The organic polymer (I) is a copolymer of ethylene oxide and propylene oxide. The organic polymer (II) is a polyoxyalkylene polymer. The organic polymer (II) contains oxypropylene units in a main chain of it. The number average molecular weight of the organic polymer (II) is 2000-50000. The organic polymer (II) is produced by ring-opening addition polymerization of an alkylene oxide in the presence of a double metal cyanide complex catalyst. The organic polymer (II) contains, in a main chain skeleton of it, a substituted amide moiety of formula (-NR5-C(=O)-) (A). The curable composition comprises 100 parts by weight of the organic polymer (II), 5-200 parts by weight of the organic polymer (I), 1-250 parts by weight of filler, 0.1-20 parts by weight of an amino group-containing silane coupling agent, and 0.01-10 parts by weight of a curing catalyst.R5 = H or monovalent organic group. EXAMPLE - Typical curable composition comprised (in pats by weight): straight-chain polyoxypropylene polymer containing dimethoxymethylsilyl group (100); butoxy-mono-terminated polyoxyalkylene polymer containing dimethoxymethylsilyl group (40); UCON LB-65 (RTM: Polypropylene glycol) (25); Ultra Pflex (RTM: Colloidal calcium carbonate) (30); Hubercarb G2T (RTM: Surface-treated heavy calcium carbonate) (100); Ti-Pure R902+ (RTM: Titanium oxide) (20); Crayvallac SL (RTM: Micronized amide wax rheology modifier) (2); Tinuvin 328 (RTM: 2-(2H-Benzotriazol-2-yl)-4,6-ditert-pentylphenol) (1); Tinuvin 770 (RTM: (Decanedioic acid, bis(2,2,6,6-tetramethyl-4-piperidinyl) ester) (1); N-( beta -aminoethyl)- gamma -aminopropyltrimethoxysilane (3); Vinyltrimethoxysilane (3); and Neostann U-220H (RTM: Dibutyltin bis(acetylacetonate)) (1.5).