Watershed management is scientific management focusing on water resource. Management is realized by means of laws, criterions, byelaws, means and so on. Watershed is a complicate system which has some characteristics such as integer, dynamic, dissipative etc., and it is important resources environment to human kind. So watershed management ought to pay attention to the variance of every component in watershed. The Yangtze River watershed management is a systems engineering. In the process of its management, we must persist in integrative management as root, scientific forecasting as base, reducing entropy value as object, environmental safety and security as kernel task. The preconditions on the synthesis analyzed of watershed components, repairing and exploitation watershed ought to base on scientific forecasting. Especially we should base on the mid-long-term disaster forecasting in start-upping floods impairment project. Reducing entropy value can increase system5s stability and ordering, and ensuring the environment safety and security can guarantee sustainable development of economy, society and ecology of watershed.