Meteorological satellites and satellite meteorology have been developed into a new era today, this paper overviews the role and impact of meteorological satellites in atmospheric sciences in different stages, as well as the challenges in science and technology to weather satellite programs. The science challenges include improving radiometric calibration and validation, developing fast and accurate radiative transfer models, assimilating atmospheric water vapor and cloud information from satellite measurements in numerical weather prediction (NWP) models and developing the advanced retrieval methodologies.