Abstract: The reservoir quality is one of key factors for judgment of existence of the shale reservoir. Taking the Qing-1 member shale of Cretaceous Qingshankou formation in Songliao basin as an example, its geochemical characteristics of source rocks, mineral content and reservoir space characteristics were studied. The results indicate that the shale of this member is characterized by high abundance of organic matter with TOC of 1%-3%, I and II1 types of kerogen, at the peak stage of oil generation, moderate content of brittle minerals, and large number of different types of pores, which not only provide effective channels for hydrocarbon expulsion, but also offer sufficient spaces for the residual oil and gas in the shale. The Qing-1 member shale has a high oil potential on the whole, and the estimated shale oil resource amounts to 78.37×108~97.97×108 t