The drilling result of GL1 and GC6 well confirmed that a set of gas-bearing strata developed in the inner Yingshan Formation in Guchengxu uplift．The lithology is mainly composed of limy dolomite and fine—grained dolomite． Through comprehensive use of cores，slices and logging data，the reservoir space mainly comprises dissolved pores， intercrystalline(corroded)pores and cracks，and the reservoir type is fractured and cavernous reservoir．The reservoir of inner Yingshan Formation is mainly affected by the lithology combination，structure crack and buried dissolution in Guchengxu uplift．Lithology combination has an important effect on the buried dissolution．The limy dolomite is conducive to the development of the reservoir，the structural fracturing is the key factor for the reformation of brittle dolomite reservoir，and buried dissolution is important constructive diagenesis by the organic acid and high temperature hydrotherma1．The study will be beneficial to the reservoir favorable area prediction of Yingshan formation in Guchengxu uplift，and has significance for guiding the further oil and gas exploration．