Abstract: The main goal of this study is to make a detail investigation of the apparent heat source Q₁and apparent moisture sink Q₂ on the Meiyu front during the period from 4 to 9 July,1991,when Eastern China had experienced a heavy rain and torrential flood process.Results show that generally there are two types of clouds which have influences on the structure of Q₁ and Q₂,i.e.convective clouds and stratiform clouds.The convective heating takes place over the heavy rain region,but the stratiform heating occurs over the light precipitation region just next to the convective region.In the convectively heating region latent heat release causes a heating peak in the upper troposphere and a moisture sink in the lower troposphere.In the stratiform region heating and drying occur above the 0℃ level and cooling and moistenning below it.Q₁ and Q₂ associated with stratiform clouds are smaller than those associated with convective clouds.