Abstract：A wide variety of geophysical information including Sea Surface Temperature (SST), Ocean Vector Winds (OVW), Sea Surface Height (SSH) and Sea Surface Salinity (SSS) can be retrieved by satellite-borne microwave sensors. Cloud is nearly transparent to microwave, and the availability of all-weather microwave satellite measurements has overcome many limitations of traditional optical and infrared measurements. The China ocean satellite 2 (HY-2A), scheduled to be launched in 2011, with primary objective of measuring SST, SSH and OVW, will significantly increase the sampling frequency over the global oceans while working together with other operational microwave satellites. This paper reviews the up-to-date ocean microwave satellite missions, outlines the future microwave missions and new technologies used to overcome limitations of the current microwave sensors, and addresses the importance of multi-dimensional observing system that combines high-resolution microwave (China's ocean satellite 3, HY-3), optical and infrared sensors as well as traditional measurements over the coastal and global oceans. It is concluded that (1) microwave measurements of SST are especially suitable for resolving mesoscale structure associated with the western boundary current systems (e.g. the Gulf Stream, the Agulhas Current) and their eastward extension into the interior ocean, where significant amount of clouds typically exist; (2) microwave measurements of surface wind are critical in understanding the mesoscale interaction processes near the oceanic fronts, and surface wind is an important physical parameter in improving the marine environmental forecasting skills; (3) microwave measurements of sea surface height have revolutionized our understanding of ocean circulations and large scale ocean wave theories. Finally, it is suggested that sustained microwave observations with resolution and accuracy at least as good as AMSR, QuikSCAT and TOPEX/Poseidon are required to understand the implications of short-term and long-term climate variability.