AbstractThe configurational change of the specially prepared graft polymer molecule occurred, when an appropriate amount of alcohol was added into the polymer solution and then evaporated it again. The graft polymer studied here was polyvinyl alcohol (PVA) with polyvinyl acetate (PVAc) branching prepared according to the procedure given in our previous papers.(1.2)The schematical explanatian of the configurational change of this graft polymer has been given. The viscosimetric measurements of the solution of the polymer of outward form have been examined and the results compared with those of the solution of the polymer of inward form. The polymer of outward form dissolved in alcohol of various strengths have their values of intrinsic viscosity the same as, but their values of Huggins' constant different from, those given by the polymer of inward form.The extent of configurational change of the polymer molecule depends on the amount of alcohol added in bringing about the change.