Abstract: In this paper, the dissipative structure and hierarchy theory are used to comprehend the endpoint of ecotoxicological effect. The hierarchical stability of dissipative structure produces the hierarchical structure of the life system, which is represented by a series of life levels. The pollution causes the fluctuation of the dissipative structure of the life system and interferes with the stability of a series of life organization, displaying a series of toxic effects on the organizations of life. The toxic effects at low levels provide a functional and developmental mechanism for that at high levels, and toxic effects at high levels are compatible with that at low levels. The endpoint at a certain life level that characterizes the toxicity of pollutants can be constructed from the endpoints at the low level, including the response of components at the low level and the response of their interactions to the pollutants. It also directly reflects the changes in components and their interactions. Furthermore, an endpoint can be involved in the construction of endpoint at a high level, becoming the toxic mechanism of life organization at the high level. However, it is difficult for an endpoint to reflect directly the changes of relationships among constituents at a high level. Therefore, the endpoint of the toxic effect has a hierarchical nature, and the endpoint at different levels has different ecological relevance. In order to characterize the effects of ecological toxicity at community level, we need to find the endpoint at the community level. Considering the discrete characteristics of complex system, we can divide the biological community into several holons that can be readily studied and observed following the principle of hierarchical decomposition. A multiscale hierarchical mechanism model that links the ecological toxicity mechanism of holons at community level to the ones at population level and below should be established. This model can provide a new way to establish the quantitative relationship between pollutant concentration and community effect, and can provide a more comprehensive and accurate way to understand and evaluate the ecological and environmental impacts of pollutants.

Key words: cotton, ecological and biological effects, biodegradable film, yield, degradation property