Mashan County, under the jurisdiction of Nanning City, Guangxi Zhuang Autonomous Region, is located in the northern part of Guangxi Zhuang Autonomous Region, the north of Nanning City, the south bank of the middle part of the Hongshui River, the north foot of Daming Mountain. It is between 107°42 '38 "~ 108°30' 00" east longitude and 23°24 '06 "~ 24°02' 06" north latitude. It borders Shanglin County in the east and Xincheng County in Laibin City in the south, Wuming District in the south, Pingguo City in Baise City and Dahua Yao Autonomous County in Hechi City in the west, and Du 'an Yao Autonomous County in Hechi City across the Hongshui River in the north. The county is long from east to west and narrow from north to south. The maximum transverse distance between east and west is 82 kilometers, and the maximum longitudinal distance between north and south is 71 kilometers. The total length of the county border is 412.27 kilometers. Mashan County covers an area of 2340.76 square kilometers. According to the seventh census, the permanent population of Mashan County was 382,430 as of midnight on November 1, 2020.

Mashan County is a hundred Yue ancient land. In July 1951, Longshan County, Nama County merged to establish Mashan County, under Binyang Special area. In December 2002, The State Council decided to abolish Nanning District, and in June 2003, it was under the jurisdiction of Nanning City. As of June 2020, Mashan County has jurisdiction over 7 towns and 4 townships, with the county people's government stationed in Baishan Town.

In 2019, the GDP of Mashan County was 8.584 billion yuan. Revenue was 367 million yuan (200 million yuan in the general public budget), and expenditure in the general public budget was 3.985 billion yuan. Investment in fixed assets grew by 23.70 percent. The per capita disposable income of urban residents is 29,031 yuan and that of rural residents is 11,844 yuan.