In this paper, the simulations of falling film behavior on a flat plate with and without interfacial gas-liquid shear stress were carried out. A three-dimensional numerical model was established based on film flow characteristics. A source term was implanted into the numerical model to take into account the interfacial gas-liquid shear stress. The model was validated by the experimental data. Both continuous film flow and film breakup were simulated. The film thickness, velocity distribution and wall shear stress at different Reynolds numbers were presented to understand the film flow behavior comprehensively. The influence of water-air shear stress on film flow behavior was revealed. A reasonable prediction on both MWR (Minimum Wetting Rate: Delta(min)) and MLFT (Minimum Liquid Film Thickness: Gamma(min)) were obtained. The model proposed in this study ought to be profitable for studies on mechanism of film breakup. (C) 2014 Elsevier Ltd. All rights reserved.