A statistical mechanics approach, namely the Ising model combined with Monte Carlo simulation, was employed in studying the process of aerosol filtration through fibrous filters. This process was modeled as consisting of numerous cells' state exchanges driven by the difference of the system energy after and before a particle moved from one cell to the other and/or deposited on a fiber cell. With the use of a simpler binary algorithm, this approach was capable of realistically simulating the complicated mechanisms involved in the filtration process. Simulations were carried out for the behaviors of aerosol particles of different sizes interacting with isotropic fiber filters of various volume fractions. Simulation results were in good agreement with reported experimental data, indicating an encouraging prospect for the method to be applied in this area.