A resin composition comprising the associated product of a polyimide resin having phenolic hydroxyl groups in the skeleton with an epoxy resin-curing catalyst, an epoxy resin having at least two glycidyl groups, and an epoxy resin-curing agent has a high bond strength, a low modulus of elasticity and heat resistance. An adhesive film comprising the resin composition is useful as an adhesive or sealant for printed circuit boards and semiconductor packages.