The successful launch of FengYun-3A (FY-3A) satellite on May 28, 2008 is remarkable in Chinese meteorological history. FY series has evolved from single instrumentation in its first generation of the polar-orbiting system to an advanced and multi-sensor platform that measures a suite of the Earth's atmospheric and environmental parameters for broader applications. FY-3A carries three atmospheric sounding instruments: InfraRed Atmospheric Sounder (IRAS), MicroWave Temperature Sounder (MWTS), and MicroWave Humidity Sounder (MWHS). IRAS has 26 channels and measures visible and infrared radiation from 0.69 to 15.5 μm. Compared to NOAA HIRS instrument, IRAS has 5 additional visible and near-infrared channels for better detection of clouds and separation of clouds from surface ice. MWTS has 4 channels, identical to MSU on board early NOAA satellites, and will allow continual MSU trending of tropospheric temperature by converting the present NOAA AMSU-A data to MSU. MWHS has 5 channels and measures microwave radiation from 150 to 183 GHz. Polarization information at 150 GHz is first time available from the satellite. It was shown from radiative transfer simulation that the polarization difference at 150 GHz is very unique for separating atmospheric falling snow from snow on the ground. In this study, we will investigate FY3 sounding data quality, intersensor calibration with NOAA/MetOp-A instruments, bias characteristics and possible sensor impacts on global medium range forecast.