The Yanchang gas field is located in the Ordos Basin of central China to the southeast of the Yishan Slope, covers an exploration area of 2.6×104 km2 and has approximately 3.5×1011 m3 of gas reserves. The gas field is dominated by lithologic gas reservoirs but also has a few structural gas reservoirs. Sand bodies were deposited in the Carboniferous Benxi Formation around offshore barrier islands and in distributary channel fillings in the delta front of the P1 s 2 and P1 s 1 divisions of the Permian Shanxi Formation. The P2 h 8 division of the Shihezi Formation contains the main reservoirs. The depths of the reservoirs are between 1 970 and 3 500 m. The Yanchang gas field can be classified as a typical tight sandstone gas reservoir filed because its porosity is lower than 10% and permeability lower than 1 mD. The discovery and development of the Yanchang gas field has led to a great increase in total natural gas reserves in the Ordos Basin. Its exploration has improved methods of locating large gas fields in deep-water depositional environments in the south part of the basin.