An application of satellite quantitative data to heavy rain and flood monitoring during June 21 to July 10, Huaihe rainfall period in 2003 is introduced. The main contents and conclusions are as follow. ① The rain belt overlaps with lower OLR value band which is from 170W·m^-2 to 220W·m^-2 , and moves northward or southward together. ②Lower OLR value band position corresponds commendably to four vapor transportation paths during rainfall period. ③ The analysis of the relationship between cross-equatorial flows, monsoon and vapor transportation is made with QuickScat data. ④ The probable position of mesoscale convective precipitation is analyzed with AMSU data. These analyses provide some new ideas for more accurate prediction of the heavy rain.