The chromatic-adaptation transform in the RLAB model by Fairchild et al. was examined. In the transform, rite chromatic-adaptation coefficients by Hunt are used for taking account of the effect of incomplete chromatic adaptation to a test chromatic illuminant. The adapting chromaticities of the coefficients were estimated for illuminants A and D65 at several luminance levels. Further, a theoretical study clarified the existence of a systematic deviation in the predicted results of corresponding colors by the transform using the Hunt＇s coefficients. The reason of the deviation was examined, and its correction method was proposed.