Abstract: Volcanic rock of the Yingcheng Formation in the Changling Fault Depression has made great contribution to increase reserve and production. Based on analyses of physical property, pore structure and seepage characteristics of volcanic rock reservoir, it has been concluded that volcanic rock reservoir in the region has low and extra-low porosity and permeability. Fracture seepage dominates in gas reservoir. Lithologic property, lithofacies and epigenesis effect of volcanic rock are the main controlling factors for physical property. Secondary pores and fractures generated during epigenesist, and were the key factors for reservoir deformation and improvement.