Since the Earth is a complex system which is composed of solid, fluid, gaseous parts. The interactions within or outside the Earth occurs at a wide spectrum of time scales. Some might be as small as a few seconds, while some might be as large as tens of years, even large as tens of thousands years. To describe such a system, possible long observational data are entailed. While near Earth satellites payloads can provide an effective observing platform for Earth monitor. As of 1994, there were only a few missions dedicated to magnetic field and gravity field researches, e.g. the MAGSAT mission implemented from 1979 to 1980. As needed, CHAMP program was firstly proposed by a German institute, GFZ, in 1994. After years of preparations, CHAMP satellite was successfully launched into the expected orbit on July, 15, 2000. This paper described the CHAMP program, of which the scientific object is mainly to refine the existent gravity models based on a lot of near Earth satellite observations, and meanwhile to conduct researches on geomagnetism and determine some significant parameters of Earth’s atmosphere; and further reviewed the possible contributions that might be made to the following aspects : Earth gravity field recovery, geoelectric field modelling, geomagnetic field modelling and atmosphere limb sounding.