A shape memory hollow body which is molded from a polyurethane elastomer produced by prepolymer process from a raw material composed of a difunctional diisocyanate, difunctional polyol, and difunctional chain extender con­taining active hydrogen in a molar ratio of 2.00-1.10 : 1.00 : 1.00-0.10, said polyurethane elastomer containing NCO groups and OH groups in almost equal amounts at the terminals of the polymer chains and having a glass trans­ition point in the range of -50 to 60°C and a crystallin­ity of 3 to 50 wt%, said hollow body remembering its as­molded basic shape but taking on a deformed shape which is given when it is deformed at a temperature higher than the glass transition point of the polymer and lower than the molding temperature and then set when it is cooled in the deformed state to a temperature lower than the glass transition point. A method of working the above-mentioned shape memory hollow body (1a) remembering its basic shape, said method prising the steps of deforming the hollow body (1a) at a tem­perature higher than the glass transition point and lower than the molding temperature and then cooling it in the deformed state to a temperature lower than the glass transition point, thereby setting it in the deformed state, combining the deformed hollow body (1b) with another member, (2),and heating the combination (3a) to a temperature higher than the glass transition point, thereby causing it to restore its basic shape and achieving firm bonding of the hollow body (1a) to the member.