China is a large country with complicated natural conditions. It is suffered from different natural disaster for a long history. Flood and waterlogging is the disaster resulting in highest loss in China. Chinese government pays more attention to flood monitoring and assessment by space technology.. since1983, NOAA (AVHRR), Landsat-TM, LANDSAT-ETM+, JERS-1, SPOT, ERS-2, Radarsat-1, CBERS-1, Envisat have been used for flood monitoring and assessment. Due to the bad weather conditions during flood, microwave remote sensing is the major tools for flood monitoring. ERS played important rule in 1998 when heavy flood occurred in the Changjiang River Basin and the Nenjiang-Songhua River Basin in China. Envisat is up to now the best satellite with powerful SAR. Its application for flood monitoring has been studied and its quinsy real-time application will be realized this year on the basis of real-time delivery of image. Together with Radarsat, it will became one of the major data sources for flood monitoring in China