In natural world, there are many complicated and elaborate systems, and ecosystems are such the most biggest systems in the world. There are two phenomena in ecosystems, one is symbiosis such as competition, predation and mutualism, and the other is evolution by genetic processes. The main dynamics of ecosystems have been generated by these phenomena. In this paper, a new model of the ecosystem with symbiosis and evolution is proposed, where the Lotka-Volterra equation is used as the symbiotic model, especially paying attention to time varying symbiotic parameters, and evolution model based on genetic processes is combined organically with the symbiotic model.