Abstract: Change of conception in climatology from “climate” to “global climate system” characterizes the development of science. Climate, now from the point-view of modern climatology, is the character of global climate system, rather than temperature, precipitation, and sea level pressure in a local site. Advancement of science and improvement of technology provided the basis for the formation of modern conception “global climate system”, namely, the manufacture of high-speed computers, the establishment of the global observational system, and the development of the global climate system model. Progress of climatology more and more closely relates to the development of society.