Using high resolution GMS TBB data and every 6h NCEP/NCAR reanalysis data,the synoptic course of a heavy rain over Beijing on 5 July,1998 was studied.Results show that the convective activity can be developed and maintained easily following the ahead of V pattern low TBB region,and there are two convective activities occurring in western Beijing on 5 July.It is also found that local variation and advective term of apparent heat sources(Q₁) or moisture sinks(Q₂) can not be neglected alone except considering both in the meantime,Q₁ and Q₂ are mostly contributed by vertical advective terms,the heat center of Q₁ is near by 500hPa,while the heat center of Q₂ is about at 700hPa.The spatial and temporal distributions of Q₁ and Q₂ which describe the strong vertical eddy heat and moisture transport during the heavy rain were presented in detail.