Abstract：By comparing the similarities and differences of characteristics and functions of rain water on the ground，Ganlan water，Qingjiang water，boiling hot water，well water first drawn in the morning and spring water mentioned in Shanghan Zabing Lun，this paper expounds that in different regions，time and space， the characteristics of water are different which include cold， hot， warm or cool in temperature， dynamic or static in state，forward or reverse in direction，light or heavy in texture，strong or mild in smell as well as the functions， reflecting ZHANG Zhongjing's concept of space- time medication that “the characteristics of water changes with time and space”.