PURPOSE: To obtain the title composition which is excellent in the adherence to a support and the balance between the adhesion to an adherend and re- releasability by compounding a specific acrylic copolymer and a prescribed amount of silicone oil.

CONSTITUTION: The title composition comprises 100 pts.wt. acrylic copolymer which contains alkyl ester of (meth)acrylic acid as a major component and a monomer containing a functional group as a comonomer, such as n-butyl acrylate-methyl methacrylate-acrylic acid copolymer, and 0.05 to 50 pts.wt. reactive silicone oil which contains a functional group reactive with the monomer containing said functional group and has a viscosity of 5 to 100,000cS, such as amino-containing reactive silicon oil.