The synthetical evaluation about that the Three Gorges Dam affects on the eco-environment of Yangtze Valley draws conclusions, they are, the unfavourable results are much more, the effects of disadvantages surpass the effects of benefits, no good result can be utilized until the project ended, but the disadvantageous effects will emerge immediately when the dam is built, however, some of them will be forever. At present, the ability of holding people has been beyond the limit in the Three Gorges area, besides that,if the big dam is built,so much effective land will be inundated, thousands of people would have to emigrate from the reservoir area. Certainly it can only be a disastrous event to have the Three Gorges Project.