Recent commercial products tend to have various appearances with curved surfaces. This is because attractive outer designs stimulate consumers' motivation for purchasing. This paper attempts to study how the bottle shapes affect our impression. The approach consists of three parts. First, three-dimensional models are fabricated to imitate shapes of widely circulated PET bottles, and thirty five examinees rate their impression by answering questionnaires. Measured objects have nine different bottle shapes with specific features. Twelve adjective pairs are chosen for the use in questionnaires to describe model features. Then, the results from the questionnaires are studied by the analysis of variance to clarify the significant differences among impressions caused by variously curved shapes. Finally, the results are analyzed by using the factor analysis to get the factor scores.