Youxi County, also known as Shenxi, was under the jurisdiction of Fuzhou when it was established in the 29th year of the Kaiyuan era of the Tang Dynasty (741), and was under the jurisdiction of Sanming City in 1983. It is located in the east of Sanming City, in the middle of Fujian and north of Dayun Mountains, and adjacent to Minqing, Yongtai, Shaxian, Datian, Nanping and Dehua. Youxi has a total area of 3463 square kilometers, ranking the second in all counties (cities, districts) in the province, and has jurisdiction over 11 towns and 4 townships. According to the data of the seventh census, as of 0:00 on November 1, 2020, the permanent resident population of Youxi County is 341638. It is the largest and most populous county in Sanming City. Youxi County is the birthplace of Zhu Xi, a famous Neo-Confucian and educator in the Song Dynasty, and the first "Millennium Ancient County" named by the United Nations Group of Experts on Geographical Names in Fujian Province.

Youxi is known as "the pearl of central Fujian", also known as "the hometown of Chinese golden orange", "the township of Chinese green bamboo", "the township of Chinese bamboo", "the township of Chinese camellia", "the famous city of Chinese leather cloth", and "the famous city of Zhuzi Confucian culture". In 2010, it was awarded the title of "Millennium Ancient County"; On July 23, 2013, the Central Party History Research Office officially confirmed that Youxi County belonged to the former Central Soviet Area; On October 22, 2018, it was included in the list of pilot zones for the integrated development of national rural primary, secondary and tertiary industries in 2018; On December 31, 2019, it was selected as a typical county for rural innovation and entrepreneurship in China.

In 2021, Youxi County will achieve a gross regional product (GDP) of 24.802 billion yuan, an increase of 7.6% over the previous year. The added value of the primary industry was 5.387 billion yuan, up 6.4%; The added value of the secondary industry was 9.2 billion yuan, up 5.9%; The added value of the tertiary industry was 10.215 billion yuan, up 9.8%.