The concept of "ecology" in a broad sense covers nature and society, and in turn "ecological crisis" refers to various imbalances and conflicts among environment, resources, population, politics, economy, culture and so on. The process of the transition from agricultural civilization to industrial civilization and ecological civilization is the process of human trying to adjust their living style passively to deal with various ecological crises rather than human's active choice. The crisis of relationship between human individuals hides behind that of the relationship between human and nature. The construction of ecological civilization concerns a series of idea transformations in the fields of nature, economy, politics, culture and philosophy; and we should take a cautious but optimistic attitude towards it.