The author give a formula of calculation whiteness on the light source colour,calculated whiteness of some typical light source with this formula,and drawed a elliptical high whiteness region on the CIE 1931 chromaicity dia- gram.

• 对几种典型光源的白度进行了计算，并在CIE1931色度图上给出了光源色高白度椭圆。 建议将白度列为白色光源的色品参数之一。