Some of the basic calorimetric characteristics of the CRT monitor were examined These characteristics are closely related to each other. It was found that; 1) CIE model works well for the tone curve characteristics when the CRT monitors are properly calibrated, 2) sRGB's standard monitor characteristics represent reasonably well for the current broadcast monitors, 3) the monitor's gamut is much larger than that of photography and printing, but it does not cover all of the photograph and printing's gamut even with the head/foot room, 4) the monitor's gamut is greatly reduced with the reflection of the ambient illumination. The CRT monitors are rather easy device for the calorimetric characterization, if they were calibrated properly. However, some compensation is necessary if the monitor's characteristics deviates from the ideal set-ups or if it were seen under light illumination.