Being centre on the ecosystem of lakes and reservoirs, based on the assessment of pressure of human activities, the ecological health of the lake and the service functions of the lake, a method system of comprehensive assessment of ecological security is proposed through rigorous theoretical derivation and model construction. Subsequently, the rationality and reliability of this method system are confirmed by the assessment of ecological security of Taihu Lake in China.

The authors analyzes the function change of urban in its evolvement and the eco-environmental problems caused by this change. Based on this analysis and the method of systems ecology founded by Odum H T, the authors discuss the aim and the principle of urban eco-environment planning under the sustainable development; put forward the general view of urban eco-environment planning in which the kernel is the adjusting of industry structure, land-use structure and spatial pattern; construct the dynamic simulating model of eco-environment planning of Guangzhou city, China which organizes the models of economy, population, the equilibrium of carbon and oxygen, and other models of atmospheric diffusion, rainwater sedimentation, vegetation absorbing to SO₂, NO_x，TSP；at last simulate the model by means of DYNAMO language and obtain the optimal program of eco-environmental planning of Guangzhou city.