Due to the severity of climatic disasters in China, the project of Research on the Formation Mechanism and Prediction Theory of Severe Climatic Disasters in China was implemented as one among the first batch of projects to gain support from the National Key Program for Developing Basic Sciences. Researches of this project started the study by examining the occurrences of severe climatic disasters such as droughts and floods in China from the 1980s, and the formation mechanism of these severe disasters was analyzed from the variations and interactions among various spheres of climate system, especially from the affecting mechanism of variabilities and interactions among the sea, the land and the atmosphere subsystem of climate system on severe climatic disasters in China, and then the new theory of the East Asian climate system associated with the formation mechanism of severe climatic disasters in China was proposed. Moreover, this project also achieved a new development on the mechanism of ENSO cycle in the tropical Pacific and the thermal effect of the Tibetan Plateau on climate variability. On the basis of these theoretical studies, a numerical prediction model of ENSO cycle and a numerical prediction system of extra-seasonal and annual climate anomalies in China were proposed respectively, and a general atmospheric circulation model to be included in a new-generation numerical climate model designed. Through the design of these two prediction systems, the prediction level of ENSO events greatly increased, and the severe drought and flood disasters occurred in the summers of 1998-2003 were successfully predicted in China. In addition, the project successfully carried out the “The Observational Experiment on the Air-Land Interaction in the Arid Regions of Northwest China”, which has provided much valuable scientific data related to the air-land interaction in the typical arid regions of Northwest China and has obtained much ordiginal and novel scientific achievements. These have provided credible scientific data of climate and environment for the strategy of opening up Northwest China. These achievements not only have established a solid foundation of theory and numerical model for proceeding the study on occurring regularity, cause and prediction of severe climatic disasters in China, but also have important economic and social benefits for increasing national prediction level of severe climatic disasters in China and mitigating economic loss due to these climatic disasters.