PROBLEM TO BE SOLVED: To provide an ultraviolet-curable tackifier composition exhibiting an excellent tackifying force of a level entailing no peeling over time from substrates consisting of various materials and excellent in terms of level difference compliancy.SOLUTION: The provided ultraviolet-curable tackifier composition is an ultraviolet-curable tackifier composition including (A) urethane (meth)acrylate, (B) (meth)acrylic monomers, and (C) a photopolymerization initiator wherein the (B) (meth)acrylic monomers include (B-1) a (meth)acrylic monomer expressed by a general formula (1) and capable of forming a homopolymer having a glass transition point of -20°C or below and (B-2) a (meth)acrylic monomer capable of forming a homopolymer having a glass transition point confined to a range of 15 to 200°C; a tackifier derived from the same is also provided.
