Cooling-induced deformation (CID) of polystyrene shells was experimentally characterized in detail. In the experiments, polystyrene shells were cooled using liquid nitrogen and observed with an optical microscope. Pictures of each shell were recorded at various temperatures, and they were compared with each other. As a result of precise error estimation, it has been found that any polystyrene shell shows CID in varying degrees. And we have recognized that some shells show poor repeatability and poor monotonicity about CID.