Haiyuan County (simplified Chinese: 海原县; traditional Chinese: 海原縣; pinyin: Hǎiyuán Xiàn; Wade–Giles: Hai-yüan Hsien) is a county under the administration of Zhongwei city in Ningxia Hui Autonomous Region of the People's Republic of China. It originally belonged to Gansu province. The county has a total area of 6,897 km2 (2,663 sq mi), and a population of approximately 360,000 people. It was the site of the 1920 Haiyuan earthquake, which killed at least 200,000 people.