Taking China as a whole, lake expansion occurred 500 B.C. (?)-0 A.D., 650-950 A.D., and 1250-1650 A.D. over the past 3000 yr. The expansions were mainly due to climatic fluctuations and correspond to frequent flood reports. Three regional characteristics of lake development have been recognized. (1) Fluctuations of near-coastal lakes, and those in other regions as well, were out of phase during 500 B.C.-500 A.D., which possibly resulted from out-of-phase fluctuations of climate and sea level on 10- to 100-yr time scale. (2) As the lower Yellow River channel migrated southward, the lakes in the south of the North China Plain formed and reached their largest sizes much later than those in the north. (3) For the lakes in the middle and lower Yangtze River valley, the higher a lake basin lies above a neighboring river and the further the lake is from the river's mouth, in general, the younger the lake is. Through land reclamation, the ancient Chinese have changed most of the lakes greatly. However, human activities were also constrained in certain ways by the natural changes of the lakes. Reclamation usually was banned and farmland was abandoned to repair reservoirs while lakes were expanding.