In order to reveal the geological characteristics of Jurassic volcano- sedimentary succession and reservoir- seal assemblage in Northeast China, and to evaluate the exploration potential of deep oil and gas, based on the present status, this paper analyzes the tectonic background of Jurassic basin in Northeast China by means of outcrop survey, drilling and logging comparison, core observation and seismic interpretation. It is proposed that the basin attributes and tectonic settings in the Early to Middle Jurassic and the Late Jurassic were different. In the Early and Middle Jurassic, it was a compressional fault depression basin controlled by the Mongol- Okhotsk orogeny, which was strongly re- formed by the late tectonics. The Late Jurassic is a volcanic faulted basin related to volcanic activities in an intracontinental extensional environment. Late Jurassic volcanic activities were frequent in Northeast China, forming a widely distributed volcano- sedimentary succession. A typical volcano- sedimentary succession developed in the Late Jurassic Tamulangou Formation in the Hailar basin that is characterized by the interbedding of volcanic rocks and sedimentary rocks that display sandstone mudstone- intermediate acid volcanic rocks- sandstone- intermediate basic volcanic rock succession. The rock assemblages in different sag units are quite different. The middle depression belt is mainly composed of volcanic rock and sandstone mudstone, while the peripheral depression is dominated by volcanic rock and glutenite.The lithology of the volcano- sedimentary succession is complex, and the reservoir rock types are diverse. There are mainly three types of lithologic reservoirs: volcanic rock, pyroclastic rock and glutenite. The physical properties of the reservoir are generally low, which belongs to medium- low porosity and extremely low permeability reservoir and tight reservoir.According to the different rock assemblages and oil- gas display of volcano- sedimentary succession, they can be divided into 4 types and 9 subtypes of oil- gas reservoir- seal assemblages. These include sandstone limestone and mudstone reservoir- seal assemblage, volcanic rock internal reservoir- seal assemblage, volcanic sedimentary composite rock reservoir- seal assemblage, and bedrock weathering crust reservoir- seal assemblage.The most favorable reservoir- seal assemblage is sandstone mudstone reservoir- seal assemblage adjacent to hydrocarbon source rock, followed by pyroclastic breccia, tuff and volcanic rock reservoir- seal assemblage of volcanic explosive and eruption facies. The dark mudstone source rocks with moderate to good hydrocarbon generation potential are well developed in volcano- sedimentary succession. The most favorable reservoir- seal assemblages adjacent to hydrocarbon souree rock distributed in the Hongqi sag and the northern Urxun sag are the main exploration fields of deep Jurassic volcano- sedimentary succession.This study can provide clarification and framework for oil- gas exploration of volcano- sedimentary succession in other areas.