Abstract: Natural fractures are important storage space and fluid-flow channels for tight oil reservoirs. They have an influence on the petroleum accumulation, enrichment, single well production and development effect of tight oil reservoirs. Analogous outcrops, cores, thin sections and image logs are used to illuminate the main controlling factors and distribution laws of fractures based on the study of fracture types and characteristics in the Lower Jurassic tight limestones in central Sichuan Basin. The results show that tectonic and diagenetic fractures are widely developed in the study area. The tectonic-shear fractures with high-dip angles are the most abundant. Most fractures are effective without entirely filled. The fracture distribution is mainly controlled by lithology, bed thickness and structure in the same tectonic stress field. Fractures are the most abundant in limestones. Then with the increasing shale content, fracture intensities gradually decrease in argillaceous limestones, lime mudstones and mudstones. In general, fracture spaces increase with the increasing bed thickness of limestones, thus resulting in the decreasing fracture intensities. Tight limestone reservoir of the Da’anzhai Formation can be divided into four combined models. Different combined models of the tight limestone reservoir present different fracture abundance. The interbeds of shell limestone with a thickness of 4～8 m and mudstone with a thickness of generally less than 5 m are the most favorable for fracture development. Fracture development degree varies in different structures.Structural high parts, such as the axis and hinge zone of anticlines, and around fault zones are the favorable areas for fracture development.