Abstract: Insisting on the essential view of structural systems controlling oil, the author engaged in the work of petroleum geology in more than 20 provinces (regions) or 40 basins in China. By many years of study and practice, the author considered that the Neocathaysian, the Western Regions, latitudinal, Qingzang reversed S type and other major structural systems control the distribution of petroliferous basins, secondary structural systems in a basin control oil-generating depressions and hydrocarbon enriched zones (regions), and varions lower order shear structure controls the distribution of oil and gas fields.