Abstract: The East China Sea Shelf Basin is a large-scale Cenozoic complex petroliferous basin in China's sea area. The Mesozoic basins there are regarded as the strategic successor for oil and gas exploration in China. In the period prior to 2005, the Cenozoic was the major exploration target in the country. After 2005, however, with the improvement of seismic acquisition and processing technology and the change of exploration ideas, a series of progress has been achieved in exploration in the Mesozoic, such as, 1) the rapid development of deep 2D seismic acquisition and processing technology; 2) the distribution pattern of the Mesozoic in East China, i.e. "the terrestrial Mesozoic in the west and the marine in the east " was established through stratigraphic correlation between the sea and the land; 3) the NE zonation of the Mesozoic basins is confirmed and the basins have passed through three evolutionary stages. 4) Two sets of source rocks are discovered in the Mesozoic. On the above basic facts, the problems and challenges of oil and gas exploration in Mesozoic basins in the East China Sea Shelf Basin are analyzed and discussed.