Abstract:Several hydrocarbon fields whose reservoir is volcanic rock have been discovered in China ,showing a new hydrocarbon exploration realm. Volcanic activity was closely related to geotectonics and basin evolution. Particularly,volcanic activity must happen in the evolution of tensile rift basin. Volcanic activity must produce volcanic sequence that has higher wave impedance than sand and mud stones,SO that volcanic sequence is characterized by strong reflections and special shape in seismic section,forming a particular seismic fades of volcanic rock. The volcanic rocks cause various anomalous seismic reflections in seismic section because of their structural shapes ,occurrence and distributions. Described in the paper are V-shaped reflection anomaly and seismic reflection patterns of sheeted volcanic rock as well as complex volcanic rocks in depression and uplift. Their geological interpretations are also recommended briefly.