The sustainable development of water resources means we should meet the needs of instream flows and keep sustained water flows and water quality of a given eco-environmental region;we should guarantee the sustainability of water resources which all lives(including human being) depending on.The necessity of government regulation in sustainable development of water resources are discussed by applying static and evolutionary game theory method by taking Shaanbei Loess Plateau as background.We also explain the functions of government regulation as manager and regulator in detail: keeping sustainability of water resources,having allocation about primary water rights,centralizing allocation to keep equality and so on.The defects of government regulation and corresponding countermeasures are also discussed.