Green Grass Islet is at the end of the north compared with the other three islets. The origin of its name can be found in the flourishing green grass in spring. In the Song Dynasty, there stood Bizhi Pavilion, villa of Shi Shouzhi, Yangcihu Private School and a hall for Officer Shi, which were later replaced by the ancestral hall of minister Fan in the Ming Dynasty. In the Southern Song Dynasty, Minister Shi, owning a house in Chrysanthemum Islet and a private school in Green Grass Islet, invited Yang Jian, one of the most accomplished teachers at that time, to teach in the school in Bizhi. Yang Jian is the representative figure of Heart-mind Theory in the east of Zhejiang Province, who was the successor of Lu Jiuyuan and inspired Wang Yangming. The two most renowned private libraries of Shi Shouzhi were Bizhi and East Louyue libraries with one in the south and the other in the north. The year of 1998 witnessed the construction of Wanghu Pavilion, Fangcao Residence and Bizhi pavilion.