Recently, the greenery at Tama Zensho-en has been discussed its background because it has been created by residents living in a Hansen’s Disease sanatorium under the isolated area. The subject of this study is a changing of greenery in Tama Zensho-en: Specifically, the changeing process of greenery, its background, memory of greenery and social image of each group. The results are as follows: when the Hansen’s Disease sanatorium was planned around Kanto region, coppice woodland as rural resources were selected as an appropriate location. During the isolation period around the opening phase in the 1910’s, the sanatorium was clearly separated from outside. Residential districts were isolated by using Earthwork fortification and planting hedges along the border of each districts, they prevented residents from escaping. In the 1960’s, when the isolation policy was mitigated, high hedges which enclosed the sanatorium were trimmed to 1.3 meters with an intention to open up the place to the local community. However, this action caused tree planting again because residents lost multiple functions of green, especially to external environments. Today while Tama Zensho-en’s forest is highlighted as a symbol of isolation and nostalgia, we clarified that its greenery had been developed with social relationships.