Abstract: The purpose of this study is to present a 2-D numerical model that solves the transient equations of flow, energy and species conservation in a single tubular solid oxide fuel cell (SOFC). Also an electrical model is considered to compute the electrical potential and current distribution in the cell. Using this comprehensive model the cell dynamic operation and response in a step load current change is studied. The simulation starts when the cell is at the steady state in a specific output load. When the load step takes place, the solution continues to a secondary steady state condition. Then the cell transient behavior is analyzed. The results show that when the load current is stepped up, the output voltage reduces to steady state in about 750s.