According to Prof. Zhu Kezhen’s(Chu. K. C) historical climatic division, the last 500 years in China can be divided into several alternately cold and warm periods. The periods of 1470-1520, 1620-1720,1840-1890 had cold winters, while those of 1550-1600,1770-1830 had warm winters. Based on such a division, in four kinds of periods, i. e cold, warm, cold-warm and warm-cold(transition period), the differences between flood/drought degree in 120 stations in China and the average of flood/drought degree in the last 500 years have been calculated. Positive anomaly indicates drought-prone area, while negative anomaly indicates flood-prone area. This historical experience provides a background to analyze the possible scenarios in the case of global warming in the future. The final results suggest that in the case of global warming the disaster of flood probably increase in many parts of China, such as southeast coastal area, the southwest, northwest, some parts of northeast and Inner Mongolia while the disaster of drought probably decrease in the North China Plain, the middle reaches of the Huanghe River and its southern adjacent area. This distribution resembles that of precipitation in warming period in this centruy and that resulted from climatic model in the case of Co₂ doubling.