For Hangzhou, West Lake is the most valuable natural and cultural heritage. However, siltation is the most severe natural problem that the lake faces, which requires the lake being dredged every few years. In history, dredging silt was mostly piled in or around the lake, and formed many famous sight spots, such as three islands in the lake, Bai Causeway, Su Causeway and Yanggong Causeway. In 1999, city government conducted a significant dredging project, and this relatively remote valley, located at the south foot of Yuhuangshan Hill, was dammed and utilized as a silt reservoir. 10 years later, the favorable micro-climatic conditions made this secluded place changed greatly, and the site became a lush woods swamp, and the habitat of some insects, birds and small mammals. The magic of this nature attract people’s attention and interest, and the government decided to transform this place into an ecological park and build a museum. In 2008, Atelier DYJG participated in the competition and won the first prize. Jiangyangfan is indeed the swamping process of an artificial lake. From the original water surface to aquatic plants germination, to the water tolerant trees’ rooting and sprouting, and to the today’s woodlands swamp with a small pond, these changes reveal the natural succession process and the awesome power of nature. Ecological Park should reflect this power and guide people to understand and respect it, and establish a harmonious relationship between man and nature. Based on the growth state of plants, some areas, named the Habitat Islands, are set aside as reserves and kept as living samples of the site’s natural succession. These islands will not be interfered and transformed in the process of park construction and future maintenance, and will provide a protected environment for small animals. For the rest of the site, moderate thinning some weak slender plants can leave more space for the stronger plants, and also can bring more sunlight into the woods, allowing the understory plants to grow better. Understory plants with certain ornamental and ecological value, such as food resources plants for animals, host plants of insects and nectar plants, are introduced to make the landscape more attractive and friendly for small mammals and insects. A boardwalk system guides the visitors into this ecosystem to experience the wonderful environment. Installed with pergolas, long benches and fences, the 1-km-long meandering boardwalk not only brought a rich visual experience, but also offered visitors a series of observation platforms and rest areas. Like any open-air Museum of Natural History, park offers an opportunity of ecological education. Today, in this once neglected valley, the fragrance of vegetation has replaced the rancid smell of the previous swamp, beautiful butterflies, bees and dragonflies have substituted for the annoying mosquitoes and other bloodthirsty insects. Newly introduced plants and existing plants are well mixed. This project demonstrates how landscape architects, after intensive studying the existing natural ecosystem, employing ecological knowledge, making scientific and reasonable interference with the site, promote it to a healthier status, limit the range of human activities, and eventually set up a regenerative ecosystem which keeps human in harmony with nature.