Puguang Gas Field is composed of the Changxing(P3) and Feixianguan(T1) carbonate reservoirs with abundant fractures, edge water and high content of sulfur in gas. To prevent edge water from entering reservoirs along fracture nets to floods, it is important to know the genesis and control factors of fractures in these reservoirs. A series of shearing and extending fractures that are relative to strata deformation and faulting have developed because of different force-source tectonic compressions from three directions since Changxing and Feixianguan reservoirs deposited in this field. It is deemed that the development of fractures was controlled by tectonism, the more intensive strata deformation is, the more fractures develop. Fracture system related with faults mostly distributes within about 1 200 m distance from faults, the closer distance from faults is, the more fractures develop. In addition, development of fractures is also controlled by lithology, strata thickness, rock constituents, and physical property of reservoirs. Different lithology results in different extent of development of fractures. Density of fractures decreases with increasing strata thickness and clast content but increases with increasing interstitial material and matrix content. According to classification of reservoirs, it is realized that fractures develop commonly in the reservoir rocks with low porosity and fractures do not develop usually in the reservoir rocks with high porosity.