The time evolution of particle size distribution (PSD)in dispersed systems is described by the General Dynamic Equation (GDE),taking accout of coagulation, breakage, condensation/evaporation, nucleation,deposition, etc. GDE is a typical partially integro-differentialequation.Consequently, normal numerical methods can hardly be used to solve it.The paper discusses the theoretical foundations, advantages anddisadvantages, and the recent development of some numerical methods for GDE,including the moments of method, sectional method, discrete method,discrete-sectional method, and Monte Carlo method. The paper paysspecial attention to the MonteCarlo method, including the ``time-driven'' Monte Carlo method, ``event-driven''Monte Carlo method, constant number method, constant volume method.