Abstract: Cangdong fault zone is the west boundary fault of Huanghua depression. It was a reverse fault in Mesozoic era and became a normal one in Cenozoic ear. It controls the structural evolution of the depression，and hence plays an important role in the transportation and enrichment of oil and gas. We analyze 23 seismic cross-sections in southern and center parts of Cangdong fault zone, obtain fault throw and strata thicknesses, by using synthesized gravity and magnetic data, quantitative researches on the structural evolution of Cangdong fault zone and the western Huanghua depression show that; Cangdong fault zone can be divided into four temporal stages and six spatial sectors. It strongly affected the conversion of western Huanghua depression. The NWW faults in the depression adjusted the conversion of structure patterns.