Ecological devastation is becoming a serious problem locally to globally, in proportion as people seek affluent living circumstances. Environmental devastation originated mainly from nature exploitation and construction of cities and industrial institutions with non-biological materials. Humans have ignored the rules of nature, biodiversity and coexistence. One of the best measures we can take anywhere, in order to restore ecosystems indigenous to each region and to maintain global environments, including disaster prevention and C02 absorption, is to restore native, multi-stratal forests following an ecological method. I would like to refer to the experimental reforestation projects based on ecological studies and their results at about 550 Iocations throughout Japan and in Southeast Asia, South America, and China. We have proved that it is possible to restore quasi-natural multi-stratal forest ecosystems in 20 to 30 years if we take the ecological method.