The present invention relates to a solid type rubber-based pressure-sensitive adhesive composition, which is prepared by adding a tackifier, a softener, and an isocyanate-based crosslinking agent reactable with active hydrogen into an acrylic rubber containing a monomer having an active hydrogen-containing functional group as a copolymerization component to thereby obtain a solventless and nonaqueous pressure-sensitive adhesive composition, and particularly it relates to a solid type rubber-based pressure-sensitive adhesive composition having the above-mentioned constitution, in which the above-mentioned acrylic rubber includes a copolymer containing butyl acrylate as a main component, and as the copolymerization component a monomer having a hydroxyl group or a carboxyl group as the active hydrogen-containing functional group.