Niumasi Town () is a township-level administrative unit under the jurisdiction of Shaodong County-level City, Shaoyang Prefecture-level City, Hunan Province, the People's Republic of China. It is located in the northwest of Shaodong City, at 111ð35'10"-111ð42'55" east longitude and 27ð13'10"-27ð19'50" north latitude. The total area is 81.64 square kilometers, with a population of 79,331 people.
Niumasi Town has jurisdiction over the following sub-areas:
The G320 National Highway, Lou-shao Railway and Tan-shao Expressway pass through the town. Shaoshui River meanders through the territory.
Niumasi Coal Mine (), now also called Niumasi Mining Co., Ltd. (), is located in the territory of Niewmasi Town. It is a county-level enterprise run by the provincial government.