Abstract:China began to study the polar orbit meteorological satellite remote sensing technology in the 1970s. To acquire the global cloud images day and night, a visible and infrared scanning radiometer is developed in 1974. The radiometer used a scanner with 48 rpm, an Si detector, and an infrared thermistor detector. At the orbit altitude of 900 km, it could generate images with ground resolutions of 3.6 km and 5.2 km respectively. In 1977, the FY-1 meteorological satellite came into its engineering development phase, a cooled HgCdTe infrared detector is used for its scanning radiometer with 120 rpm. Its ground resolution had been improved to 3.2 km. With the improvement of the performance of HgCdTe detectors and the progress of digital technologies, China began to develop a 5-channel scanning radiometer with 360 rpm which had the same performance as that of the Advanced Very High Resolution Radiometer (AVHRR) onboard of TIROS-N satellite in 1981. Among the five channels, two channels were used for ocean color observation and had the ground resolution of 1.1 km. In September 1988, the FY-1A satellite was launched for the first time. Later, the scanning radiometer onboard of the FY-1B satellite was launched in September 1990 and was in stable operation for two years after. The visible and infrared images acquired were very clear and their infrared radiant calibration accuracy was better than 1 K. To meet the needs of meteorological and ocean color observations at the same time, China began to develop a Ten-channel Scanning Radiometer. The instrument not only has six channels similar to those channels of the AVHRR/3 onboard the NOAA satellite, but also has four channels used for ocean color observation and atmospheric correction, respectively. The instrument was installed onboard of the FY-1C and FY-1D meteorological satellites launched in May 1999 and in May 2002, respectively. They were in stable operation and acquired clear images for more than 4 years and more than 9 years, respectively. To develop new remote sensors and improve the observation ability of polar orbit meteorological satellites, China carried out a series of remote sensing tests for a medium resolution imaging spectrometer, a multi-mode microwave remote sensor, a solar ultraviolet spectrum detecting instrument, and an earth radiation budget measurement instrument onboard of the SZ-3 and SZ-4 spacecrafts launched in 2002. It also developed an infrared atmospheric sounder which had laid the technical basis for its polar orbit meteorological satellites to transform from two-dimensional imaging observation to three-dimensional stereo observation. The second generation of operational meteorological satellite FY-3A was launched in May 2008. It carried ten remote sensing instruments in total, including a Ten-channel Scanning Radiometer, a Medium Resolution Imaging Spectrometer, an Infrared Radiation Sounder, a Microwave Temperature Sounder, a Microwave Humidity Sounder, a Microwave Imager, a Total Ozone Unit, a Solar Backscatter Ultraviolet Spectrometer, a Solar Irradiance Monitor, and an Earth Radiation Monitor. The data acquired were used both for weather forecast and for climate change study. The medium resolution imaging spectrometer had 20 detecting channels. Among them, four visible channels and one thermal infrared channel had a ground resolution of 250 m which could be used for fast, repeatable, and finer observation of global surface.