The goal gratings of five frequencies with different mean luminance were displayed on a CRT display，the contrast detection thresholds under different condition were measured for 9 young observers，and the curve reflecting the relationship between luminance and contrast detection threshold was obtained. Thus，human vision characteristic for transferring luminance was discussed in the range of luminance of CRT. The experimental results showed that the contrast thresholds of different observers were very similar for gratings with frequencies of 3.79 and 4.97cpd，while they were quite different for gratings with frequencies of 1.23，1.97 and 9.86cpd，and the contrast detection threshold could be lowered by increasing the luminance of grating，but the resolving power went to a limit with the luminance increasing，and effect of the CRT display matched with human vision characteristic very well when the luminance was 60cd/m2. The results would make a good foundation for research and application in image manipulation，display manufacture，photography，printing，color matching and so on.