It is important to investigate the influence of the presence of solid particles on gas flow, known as two-way coupling in gas-particle two-phase flow, because this influence may result in a considerable modification of the heat transfer performance in facilities such as tube bank heat exchangers. There is not yet available data with detailed information on two-way coupling interaction in tube bank systems for model validation. This paper presents a computational study of two-way coupling gas-particle flow in the tube bank system using a two-way coupling model previously developed by the present authors. Comparison of one-way coupling prediction for both gas and particulate phase in an in-line tube bank system is made with experimental data. Then, the effect of the presence of particles on the gas flow properties in this tube bank system is studied in terms of particle sizes and loadings. It is found that both the mean and turbulent flow of the gas phase in the tube bank are modified significantly due to the presence of solid particles; and the modification depends to a great extent on the particle sizes and loadings.