The all porous solid oxide fuel cell concept is proposed to solve the carbon deposition problem of solid oxide fuel cells. The transport of oxygen molecules from the cathode to the fuel side through the porous electrolyte can resist carbon deposition but could reduce the fuel cell performance. In this paper, a two-dimensional model for all porous solid oxide button cells is developed for the first time. After model validation with experimental data, the model is then extended for a tubular cell for parametric simulations. The effects of operating conditions and the electrolyte microstructure properties on carbon resistance and electrochemical performance of all porous solid oxide fuel cells are examined. The good carbon resistance of all porous solid oxide fuel cell is numerically demonstrated. It is found that the electrochemical performance and anode surface O/C ratio is significantly affected by anode inlet gas composition and flowrate. In addition, the anode supported all porous solid oxide fuel cell shows a great potential in terms of both power generation and coking resistance. The results of this study form a solid foundation to understand the mechanism and promising future of all porous solid oxide fuel cells.