Based on the analysis of dynamic breakup process of particles in particulate systems, a direct stochastic simulation method is proposed in this paper, which is applicable for general population balances with particle breakup. The detailed algorithm is presented. There are two important steps in algorithm : 1. to determine whether a particle breaks up, using the breakup frequency function; 2. to determine the volume of daughter particles for one breakup, using the probability distribution function of daughter particles after the breakup of a mother particle. A calculation example of turbulent liquid-liquid dispersion is given to predict the development of particle size distribution. The calculation results are in very good agreement with the analytical solution from Das (1996).