To provide a moisture-curable composition which has elasticity and a shortened curing time, to provide a sealing material, and to provide an adhesive.

This curable composition comprises (a) a vinylic polymer having cross-linkable silyl groups represented by formula (1): -[Si(R1)2-b(Y)bO]m-Si(R2)3-a(Y)a [R1 and R2 are each an alkyl, an aryl, an aralkyl, or the like; Y is OH or a hydrolyzable group; (a) is 0 to 3; (b) is 0 to 2; (m) is an integer of 0 to 19, where (a)+(m)(b)≥1], at the terminals, and having a number-average mol.wt. of 3,000 to 100,000 and a glass transition temperature of 20 to 150°C, and has a dynamic viscoelasticity (application frequency: 10 Hz, strain: 1%) storage elastic modulus characteristic E' of ≤105 Pa at temperature of 50 to 200°C and ≥106 Pa in a temperature region of ≤50°C. The curable composition can also be used as a hot melt adhesive or a sealing material.