A photocurable pressure-sensitive adhesive composition, a photocurable pressure-sensitive adhesive layer, and a photocurable pressure-sensitive adhesive sheet including a support and such a photocurable pressure-sensitive adhesive layer formed on at least one side of the support are provided. The photocurable pressure-sensitive adhesive composition can form an adhesive layer that has sufficient initial adhesive strength through the process of drying and cross-linking without having any adhesive protruding at normal temperatures and pressures, hardens easily with light irradiation, and has a high peeling resistance. The photocurable adhesive composition contains a graft polymer that graft-polymerizes a monomer containing a cyclic ether group to a (meth)acrylic polymer and a cationic photopolymerization initiator. The photocurable adhesive layer and the photocurable adhesive sheet are prepared by using said photocurable adhesive composition.