The Younger Dryas Stadial，11 000-10 O0O a B P，is the most remarkable catastrophic environmental change in the circum-north Altantic region since  the Last Deglaciation．It is characterized by the sudden return of glacial climate．and deteroration of environment．Plenty of terrestrial evidence for the abrupt environmental deterioration found in Northwest Europe and also North Ameirca．There are indications of ice-sheets readvance and renewed glacier activities in the mountain regions．Periglacial condiitons returned to many lowland areas and scrub tundra developed．Fossil records show that the YD event caused the extinction of the mammoths-woolly rhino funa．Reconstructed high-resolution time series of the climaitc changes during the last deglcaiation now proves that the Younger Dryas event occurred during the time with highest solar radiation in the North Hemisphere，it was too abruptly to have been directly forced by the orbital dynamics．It is now attributed to the non-linear feedback in the interaciton system of the atmosphere-ocean-ice sheet-land-bioshphere．The flickering switch of the deglaciation climate must have been triggered by the ice sheet behavior，the melting rate,iceberg discharge and ocean-atmosphere heat flux/surface water circulation in and around the North Atlantic. The change in ocean-atomsphere-land carbon budget could also be a forcing factor in this short-lasting climatic change.Thus the study of the Younger Dryas mechanism may be able to provide some clues to the global worming facing us at present.