Abstract: The direct cause of agricultural land waste is the insufficient labor power and inconvenient of tilling, etc. The deep-root cause is the higher and higher of agricultural cost, among which the most influential is the water supply. Water supply is closely related to land system. Since the open and reform, the property right of collective land is continuously weakened, the system of rural government attached to land has thus changed, and the water supply ability in rural organizations is hard to avoid. Under the situation of “triple-rights allocation”, the turn of business right is not necessary to bring about scale management, and cannot organize the scattered peasants into a subject with common interests appeal to effectively solve the problem of water supply. By the experience of agricultural land system in different places, the choice of mode of land system must be concerned to “water-land” relations, to water supply, to have a best structure of land property rights, to activate the interests correlation between peasants and village collective, to arise peasants’ subjectivity, to re-build the ownership of collective land, and to re-construct rural organization system.