A first principle one-dimensional (1-D) dynamic model for tubular solid oxide fuel cell (SOFC) is developed. To convert the distributed model into a control relevant nonlinear state space model, an approximate analytical solution for reacting gas-flow problem is proposed, and applied to the 1-D SOFC dynamic model. Compared to numerical solutions, the proposed solution can significantly reduce requirements in computation, and thus, facilitate dynamic simulations and control applications. Distributed dynamic relations between current density and electromotive force (EMF) are investigated. Diffusion, inherent impedance, primary flow, heat transfer, and internal reforming/shifting reaction are considered simultaneously. Dynamic responses of the interested variables when external current, fuel and air inlet streams are perturbed by step changes are investigated through simulations. (C) 2008 American Institute of Chemical Engineers.