Keyuan Garden was built in the 30th year of Qing Daoguang (1850). Its plane is irregular polygon, covering an area of about 2,204 square meters, with a building area of 1234 square meters. All the buildings are arranged in groups along the peripheral sideline, and the "spacious townhouse" encloses a large garden space with closed outside and open inside.
According to the needs of function and landscape, buildings can be roughly divided into three groups. The southeast hall complex, where the entrance is located, is the hub for receiving guests and people. Centered on the foyer, there are buildings such as Red Pavilion, Caotang, Grape Forest Hall and Tingqiuju. The pavilions in the west are banquet places, overlooking and cooling off the heat, with double clean rooms, osmanthus room (Kexuan), kitchen and waiter room. Beitang Group is a place for sightseeing, living, reading, playing the piano, painting and poetry. There is a veranda by the lake, named Bo Xi Yu Yin, and other buildings, such as Tangke, Wenhua Courtyard, Chu Yue Chi Pavilion, Luqi Building, Xike, Shiwo, Diaoyutai and Guest Pavilion.