Abstract: The interaction between soil mass deformation and pore water pressure during subsidence by mining is studied in this paper by theoretical analysis,laboratory tests, and in situ measurements. The results show that the generation and dissipation of super static pore pressure are caused by the variations of stress and deformation in soil mass along with the mining progress. Compressive or expansive deformation occurs and grows with time of mining. The compression and expansion may be superimposed on each other in different parts of soil mass and sometimes on the subsidence caused by drawdown of groundwater level in bottom aquifers. The study reveals a mechanism of subsidence by mining in mines with thick water bearing soil layers and is of significance in subsidence prediction and mining under water body.