Abstract: In this paper,a new three-dimensional dynamics and electrification coupled model from reference 1 has been used for simulating a thunderstorm process by observations of July 19,1981 CCOPE(Cooperative Convective Precipitation Experiment).Itanaly zes the spatial and temporal development of electric structure within the thunderstorm and development mechanism,and discusses the interactions between electrification,convection and rainfall.Results indicate that inductive and non-inductive charging mechanism play a main role in evolution of electrical structure within thunderstorms,and the electric development depends highly on icephase microphysical processes.The appearing time of maximal electric field is the same as appearing time of maximal solid rainfall density,but later than liquid and maximal ascending velocity.And the appearing time of maximalelectric field is also the same as starting falling time of maximal ascending velocity.The interactions between electrif ication and convection mainly are that the convection can affect condensation and freezing processes in the clouds.