Oceanic Anoxic Events (OAEs) occurred during Aptian Albian, Cenomanian Turonian boundary and Coniacian Santonian, namely the OAE1, 2 and 3, with the OAE1 being further divided as OAE1a, 1b, 1c and 1d. But only the OAE1a and OAE2 reached to a global scale with others being limited in the Atlantic and Tethyal realm. Cretaceous OAEs usually corresponded to the positive excursion of carbon stable isotope in the marine carbonates, rapid turnover of marine biota and large scale distribution of organic carbon enriched black shales, which indicated wide ranges of changes in paleoenvironment and paleoclimate. Though the genesis of each OAE was somehow different, it is usually thought that Cretaceous OAEs may have been related to the igneous activities from the Large Igneous Provinces (LIPs). The CO2 content would have increased; chemical weathering and hydrological cycle would have been accelerated with the higher input of nutrients to ocean as the results of igneous activities of LIPs occurred at certain times of Cretaceous. The ocean would have got productive and prone to become anoxic in the deep water. The rapid positive feedbacks between the ocean primary productivity and ocean anoxia, due to the coupling of carbon, phosphorus, oxygen and sulfur cycle, would have contribute to the expansion of ocean anoxia to a global scale (for example the OAE1a and 2. The different OAEs might have different implications for the evolution of Cretaceous ocean-atmospheric system: the OAE1a marked the beginning, OAE2 signified the peak, and OAE3 indicated the decline of the greenhouse climate during Cretaceous. Due to enormous burial of organic carbon, the OAEs would have much effect on the atmospheric /oceanic system such as the decrease of CO2 and increase of O2, accompanied by the global cooling and enhancement of oxidation potential of the deep ocean. The causes, processes, and consequences of OAEs still need to be elucidated though more than 30 years has passed since it was put forward for the first time. Multidisciplinary studies are to be done for these OAE1 (a, b, c, d), 2 and 3, to get the important information on the CO2 contents, seawater temperature, nutrient status, the change of sea level and biota when they occurred. The terrestrial response to the OAEs has also been studied in succession. Chinese scientists are expected to contribute much to this issue.