Abstract: The artificial ecological system of "Forcst-Fruit-Fish" within a watershed at different altitudes has special ecological significance. Compared with other kinds of systems, it has more close material cyclings and the lowest nonproductive output and at the Same time, the greatest utilization of natural resources. During the course of optimization, the relations between the structure and function should be fully under-stood and the problems of the system stability, the elasticity of the compoucuts, the choice of tree species and their potimum proportion should be carefully studied.