A cationically polymerizable liquid composition is formed from a cationically polymerizable mixture (A) and a solid resin (B) that is compatible with the mixture (A) at room temperature and has a softening point of at least 40° C., so that the composition has a viscosity at 25° C. of 20 Pa·sec or below. The cationically polymerizable mixture (A) is formed from a monofunctional monomer (A-1) having in the molecule only one cyclic ether structure represented by formula (1) below, a polyfunctional monomer (A-2) having in the molecule at least two cyclic ether structures represented by formula (1) below, and a latent cationic polymerization initiator (A-3). A tacky polymer formed by cationic polymerization of the composition is also disclosed. (In formula (1), n denotes 0, 1, or 2, and R1 to R6 independently denote hydrogen atoms or hydrocarbon groups, which may have a substituent.)