Abstract: The microstructure of vacuum-sintering bodies of deoxidized water atomizing CPM10V prealloy powders at a series of temperature has been observed with optical microscope.The results show that the original boundaries vanish when sintering temperature is above 1250℃。The carbides are fine and uniform but the pores are larger and more when the sintering temperature below 1270℃.Apart of carbids coarsen rapidly,there are two groups carbids with a quite different size and less pores of smaller size when the sintering temperature above 1280℃.These microstructures result from two different mechanisms of solid phase and liquid phase sintering.