Using a new type of divergence equation which is derived by Chen Zhongming(2008) and the NCEP/NCAR1°×1° reanalysis data to analyze the Barotropic non-equilibrium force and the Baroclinic coupling forces at the process,the persistent heavy rain in Sichuan and Chongqing during 16-20,July,2007,compared with the 1-hour and 6-hour observed precipitation and TRMM ancillary data products.The results show that:i)The heavy rainfall mainly happen at the stage when the area atmosphere's stratification is neutral or li...