In order to describe microscale flows in compact porous media with lattice Boltzmann method,we extend a model proposed by Guo et al designed for micro gas flows in a single channel to porous medium.The extended model is used to simulate two simplified porous structures.Dependence of permeability on Knudsen number and averaged pressure is studied and analyzed theoretically.Simulated results are consistent with experimental results reported.It shows that the lattice Boltzmann method can serve as a promising tool for simulating gas flows through a compact porous medium.