This paper is to highlight a series of important developments in the study of "Past Global Change" in the recent years. The developments include:(1)extraction of high resolution environmental information for last glacial cycle;(2)establishment of high precision analytical methods;(3)suggestion of concepts of climatic instability and etc. (4)the start of comparison study of Northern and Southern hemispheres crossing the equator.
    Through the studies of ice cores such as GRIP, GISP2 and Vostok, deep sea cores, loess and vein calcite of Devils Hole, the historic picture of climatic instability can be reconstructed. On the background of glacial-interglacial cycle that is driven by orbital foring, the large amplitudes and high rates of temperature shifts reflects that climatic system is operated by more than one switch. Furthermore, some hypotheses such as climatic frequent oscillation caused by internal non-linear feedback of atmosphere-ice sheet-ocean system, climatic instability and asymmetric aperiodic change have been proposed.