Although the Middle Yangtze fold belt of the western Hunan and Hubei area has been considered to be the most important region of shale gas exploration in Hubei，the exploration maturity of shale gas is low，especially in the Cambrian and the Precambrian formations. Transgression happened rapidly in Changyang area during the Cambrian and early Ordovician period，which caused a wide development of organic-rich black shale and calcareous shale in the Niutitang Formation of Lower Cambrian under the background of deep water continental shelf. Based on results from observation of field outcrops，microscopic observation of thin sections and stratigraphic correlation，the Niutitang Formation was divided into three segments according to lithology，and the formation become thicker from south to north，developing 100 m thick relatively stable black mudstone and black shale. Geochemical analysis，reservoir property and gas isothermal adsorption experiment show that the black mudstone and shale in the Niutitang Formation have higher abundance of organic matter，higher maturity of organic matter，better kerogen type for gas formation，higher content of brittle minerals，well developed organic pore and intragranular poreand relatively developed microfracture. The gas was adsorbed tightly by the shale during the simulating experiment. The mudstone and shale is characterized by low porosity and permeability，so it is regarded as low and extra-low porosity and extra-low permeability reservoir. In the study area and its adjacent region，the Niutitang Formation is regarded to be the next target of shale gas exploration for its moderate buried depth，gentle occurrence and fewer faults structures.