Tuyin (徒隱) was a county in Youbeiping Commandery, You Province, on the northern frontier in what is now northern Hebei. Some accounts record Cheng Pu, one of Sun Jian and Sun Ce’s earliest generals, as coming from Tuyin. The precise location of the county is now uncertain, but it formed part of the line of commanderies facing the steppe to the north.
Tuyin, Youbeiping Commandery 右北平徒隱
County in Youbeiping Commandery, You Province; associated with Cheng Pu.