Abstract: The drainage system is self formed by flow on certain geology, terrain and climate conditions, with obvious characteristic of self organization.In this paper a cellular model is developed to simulate the form and the development of the drainage system.By changing geology, terrain, and climate conditions, many drainage systems are acquired which coincide with the natural river system.The river system forming process is simulated by combined with the union water trough reality.A similar drainage system is also got on the basis of the flume experiments.A simplified model is formed, too, to simulate the development process of the Alake area, east Kunlun mountain, the headwaters of the Yellow River, and the result proves to be effective.