Clouds are crucial regulators of both weather and climate. Properties such as the amount, type, height, distribution and movement of them have an impact on the earth's radiation budget and the hydrological cycle, thus cloud observation is very important. The disadvantages of zenith pointing measuring instruments and whole sky visible imagers limit the application of them. A summary of the actuality and application of ground-based whole sky infrared cloud measuring instruments and analyses of the techniques of radiometric calibrations, removal of atmospheric emission and calculation of cloud cover, amount, type are conducted to promote the automatically observation of the whole sky. Fully considering whole sky infrared cloud sounding theories, techniques and applications, there are still a lot of studies on improving the properties of instruments, enhancing the techniques of cloud base height measurements and establishing instrumental cloud classification criterion before actual operations.