Abstract: Use NCEP 6－hour reanalysis data(1°×1°) and conventional observation data to analyse a rainstorm process in northerast Sichuan Basin in June 2，2014．And compared with the process happened on May 1～2，2011 in wind and temperature．The results show that:(1) The heavy rain is mainly caused by the cold advection after cold vortex in North China and warm moist air guided by southeast air flow and cold air guided by low－level easterly airstream．(2) By low－level easterly airstream，the cold air in North vortex was leaded to Sichuan in both process．There is a good corresponding relationship between easterly airstream and the rainfall area．(3) The key area of strong precipitation had been in a high humidity condition in the whole process．(4) The low level moisture mainly drived from east to west and from south to north．(5) The moisture from below 400hPa are all convergence in the strong precipitation outbreak period and continued to strengthen in mid－high levels．