|Nature and greenery spaces are especially required in the high-density residential areas of Megalopolis in Japan. People are looking for rich greenery spaces and they are requiring for the preservation of the greenery space in redeveloping areas. But people have recently found that parks often were too crowded, when they visited them for enjoying a quiet greenery environment. Almost all old Japanese cities have parks in traditional garden style, which have been opened to the public since Meiji revolution, i.e. a hundred years ago. Originally, the gardens were possession of the Daimyo, i.e. the feudal lord, and they were enjoyed privately. Recent increase in visitors destroyed the original use pattern and the unique atmosphere, and this, of course, confused the management of the park administration. The administration and the users therefore encouraged investigations concerning the appropriate management of park as a pleasant environment. To find a preferable carrying capacity of green spaces, the impression of congestion and quietness was analyzed in a traditional Japanese garden, using the number of visitors as an indicator. The following results were obtained. The impression of congestion is significantly correlated with the number of visitors in the park, and 700 persons on 7 hectares generates the impression of congestion for a half of visitors. To satisfy the impression of quietness for more than a half of visitors, their numbers must be reduced to less than 400 persons for 7 hectares. The decreasing in number of visitors provides a more efficient impression of congestion than that of increasing.