He was born in Gaomi, Beihai Commandery (modern Weifang, Shandong), and was a student of Ma Rong, together with Lu Zhi.
Zheng is notable for his syncretic attempt to bridge the two centuries of rivalry between the two schools.
He adopted the strengths of each school in the interpretation of the Confucian classics although he usually favored the Old Text teachings.
Both schools did not survive the chaos, but Zheng's conception of Confucianism would be the mainstream interpretation for centuries.
The commemorative shrine of Zheng Xuan in Shandong was rebuilt under supervision of Ruan Yuan (阮元; 1764–1849) in 1793.