Abstract: The changes of color at different parts of the ligulate corolla and among the different whorls of the ligulate florets of red-，yellow- and white-flowered chrysanthemum cultivars were analyzed. It was found that the color of the medium part of the corolla of each ligulate floret is representative for the whole ligulate corolla，and the ligulate florets in the middle whorl are representative for the whole capitulum. The 120 chrysanthemum cultivars were randomly selected and measured the lightness L* and chromatic components a* and b*. The values of lightness L* and chromatic components a* and b* of the obverse side of the ligulate florets are closely positively correlated to the values of the reverse sides，and the ranges of the values of the obverse side are greater than those of the reverse side. It is thus better to use the color value of the medium part of the obverse side of the ligulate floret to define the flower color accurately. Analysis of the three-dimensional scatter plots revealed some chrysanthemum cultivars as having rare flower colors，which constitute important resources for breeding chrysanthemum with novel flower colors.

Key words: chrysanthemum, ligulate floret, flower color, colorimeter