The dynamic evolution of particle size distribution (PSD) along the longitudinal length of electrostatic precipitator (ESP) quantitatively describes the collection process of ESP, and then is capable of estimating the performance of ESP. The details of the evolution of PSD are obtained by the solutions of population balance equation (PBE) for electrostatic collection. The paper promoted a stochastic method to solve the PBE. The method is based on event-driven technique and introduces the concept of weighted fictitious particles. The halving procedure of number weight of fictitious particle is adopted to restore the statistical samples of the stochastic approach and maintain the computational domain. The method, which is named event-driven constant volume (EDCV) method, is used to simulate the collection process of particles in a small-scale single-stage wire-plate ESP, considering simultaneously the electrostatic force, the convection force and the transverse particle diffusion in the model of collection kernel. The agreement among the results of the Monte Carlo method, the experimental data and the results of method of moments is good. (C) 2007 Elsevier Ltd. All rights reserved.