The purpose of this study is to find out the characteristics of building materials and exterior colors of the traditional palaces in Korea and Japan. Nijo-Castle in Japan and Changdeok-Palace in Korea were selected for the subjects of the study. For the color measurement and analysis, NCS color system was used. The results of this study are as follows. In Changdeok-Palace, Korean pine woods, granites, tiles, blue tiles, clays, Jeon-dol(Korean unique tiles for fences and ground), lime powders, straws, Korean traditional papers, bronze were used for building materials. In Nijo-Castle, however, Japanese pine woods, granites, tiles, clays, lime powders, straws, Japanese traditional papers, bronze and golds were used. As for hues in Changdeok-Palace, Y to R, G ∼ G30Y, R80B∼B, B to G were used mainly, and in Nijo-castle, Y to R, B80G∼B90G, G30Y were found. As for tones in Changdeok-Palace, every kinds of tones were used except 'Deep chromatic' and in Nijo-Castle, 'Greyish chromatic', 'Toned light grey', 'Dark deep', 'Toned dark grey', 'Toned grey' were used. At this study, the building materials and exterior colors were analyized between Changdeok-Palace and Nijo-Castle. And from the results, it is expected that we would understand different cultures of two nations, and get the concept of making their own unique characteristics.