To provide a carboxylic acid-modified polyolefin resin composition which has excellent adhesive strengths for example, on both highly polar and low polar base materials, provides an excellent adhesive strength to a material with a highly acidic surface for example, such as carbon fibers, and has a water resistant adhesive strength with such a level that does not generate peeling with time caused by the effect of hot water or the like.

The carboxylic acid-modified polyolefin resin composition is characterized by having an acidic value of 100-300 and including a carboxylic acid-modified polyolefin resin (A) having an amino group.