Changhai County (simplified Chinese: 长海县; traditional Chinese: 長海縣; pinyin: Chánghǎi Xiàn; literally "Long Sea") is a county under the administration of Dalian city in Liaoning Province of the People's Republic of China. It consists of several islands in the Yellow Sea and is located offshore of the Liaodong Peninsula. There are 112 small islands and reefs in the county, traditionally called the Outer Chang Mountains Island Chain. The county has a total area of 119 square kilometers, and a population of approximately 80,000 people. The county's postal code is 116500, and the county government is located in the Dongshan neighborhood of the town of Dachangshandao.