Abstract: With core, thin slice and other analysis methods, this paper analyzed the characteristics of Cretaceous volcanic reservoirs in the Saihantala Sag of the Erlian Basin from lithology, lithofacies, pore type, reservoir heterogeneity, etc. After establishing the relationship between geology and seismic data, this paper predicted some favorable reservoirs of the study region through seismic inversion and seismic attribute analysis methods such as frequency-divided inversion, correlation length analysis and so on. The results showed that volcanic rocks mainly developed in Member 3 of A'ershan Formation of the Lower Cretaceous in the Saihantala Sag, with andesite as the main lithology. Reservoir space types included pores, apricot kernel inner pores, dissolved pores, shrinkage cracks and structural fractures; pore-fissure associations included pore type, fissure-pore type, fissure and vuggy type, fissure type; eruption facies were widely distributed while explosion and volcanic sedimentary facies distributed limitedly; the upper subfacies of eruption facies had excellent reservoir and oil-bearing property; favorable reservoirs distributed along the Zhabu Fault and the upper part of the Member 3 of the A'ershan Formation of the Lower Cretaceous of Sai-60 well block showed great potential; hydrocarbon accumulation model belonged to the model that faults transported hydrocarbon and reservoirs located outside source rocks.