Ravel's "Bolero" consists of 18 pieces. In "Bolero", only two melodies are each repeated nine times, with changing instruments in the orchestration. In our experiment, 13 listeners rated their perceptual impressions of each of the pieces on 25 semantic scales, such as bright—dark, strong—weak, and expressive—simple. The experimental data were analyzed by Kruskal's multidimensional scaling program and a multiple regression analysis program. Analysis of the data showed that each of the 18 pieces could be arranged on a two-dimensional perceptual space and that the first and second dimensions corresponded to feelings of powerfulness (quietness) and such expressive feelings as comic (serious), sticky (flowing), and coquettish (reserved). Relationships between the perceptual impressions and the orchestration were discussed.