Abstract: In order to reduce the effect of environment on the physical and psychological of drivers and passengers. The authors, on the basis of combination of color science and the basic theory of psychology and the highway traffic practice， detailedly expound the color effect of highway landscape and such psychological effect of color, as temperature sense， bloating and contracting sense, advance and retreat sense, excitation and fatigue sense, etc. The conclusion indicates that color theory should be correctly utilized in the design of landscape of highway. It can reduce the potential traffic accidents and bring comfort and joy to drivers and travelers.