Abstract: Volcanic rocks dominated by eruptive facies are developed in the third member of Aershan formation of Jurassic in Saihantala sag in Erlian basin, with thin thickness and few wells penetrating into the rocks. It is suggested from well data analysis that there exited four stages of volcanic eruptions in Aershan period. In view of the strong heterogeneity of such volcanic rock bodies, this paper presents the exploratory application of frequency?divided imaging technique to the identification of volcanic eruption cycles. By improving resolution of the seismic data, the scale and thickness of each eruption cycle are effectively predicted, providing a powerful support for petroleum exploration of volcanic reservoirs in this area