Based on the core, thin section, scanning electron microscopy, well logging and the physical properties of reservoir, according to the research on the volcanic reservoirs characteristics of the E2-3S3 Formation in Oulituozi area, obtaining the following points: Basalt, trachyte and tuff are mainly lithology, overflow facies are main lithofacies, secondly explosive facies and volcanic sedimentary facies; Secondary reservoir spaces are often superimposed on the original reservoir spaces, and pore, hole and slit together form the effective reservoir spaces; The reservoir property show that the trachyte are the best, secondly the basalt and tuff; Reservoir lithology, lithofacies, thickness, fracture development, physical and electrical properties and other reservoir parameters are the main evaluation criteria to conduct the reservoir comprehensive evaluation.