PURPOSE: To obtain the titled dispersion excellent in flame resistance, heat resistance, bonding strength, mechanical properties, applicability, etc., by polymerizing a radicalpolymerizable monomer in an organic liquid in the presence of a specified alkoxypolysiloxane resin.

CONSTITUTION: At least one radical-poymerizable monomer (A) [e.g., (meth) acrylic acid] and 0.5W70wt% alkoxy group-containing alkoxypolysiloxane resin (B) of a average MW of 1,000W100,000 as a dispersion stabilizer are dissolved in 70W30wt% organic liquid (e.g., pentane) in with component A is soluble but its polymer is insoluble. To this solution, 0.2W10pts.wt., per 100pts.wt. component A, radical polymerization initiator (e.g., 2,2-azobisisobutyronitrile) is added, and the mixture is dispersion-polymerized at 60W160°C for 1W15hr.