Lava, which is common in the stratigraphic section, often forms important oiland gas reservoirs in down--faulted petroleum basins in eastern China. Based ondetailed studies of cores from Lower Tertiary lava flows in the Changwei basin,Shangdong Province, vertical facies structure models of "primary", "weathered" and"subsided" lava units are suggested in this paper. Besides, a method for recognizinglava flow units and various lithofacies in the three lava units by constructing afumarolecontent curve is proposed in this paper. These make the lithofacies and"unit" recognization more practicable than the traditional "three--zone model" and"four--zone model", and, thus will be conducive to the study of volcanic reservoirsand establishment of their vertical facies models.