Does Dongji Island belong to Shengsi Islands?

Belong to. Baidu map shows that Dongji Island is located in Shengsi County, Zhoushan City, Zhejiang Province, which is a part of Shengsi Islands, an island at the middle and eastern end of Shengsi Islands, and a scenic spot focusing on marine tourism and leisure. Therefore, Dongji Island belongs to Shengsi Islands. Shengsi Archipelago, the island under the jurisdiction of Shengsi County, is located in the east of Hangzhou Bay and southeast of the Yangtze River estuary, and consists of hundreds of islands at the intersection of Qiantang River and the Yangtze River estuary.