Tang is a pinyin romanization of various Chinese surnames.
Chinese surnames commonly romanized as "Tang" include Táng (唐) and Tāng (湯/汤).
Tang is also occasionally used to romanize Deng (鄧/邓, Pinyin: Dèng) and Teng (滕, Pinyin: Téng), especially for persons of Hong Kong origin, based on Cantonese pronunciation.
Tang can also be used to romanize the surname Zeng/Tsang (曾, Pinyin: Zēng), based on Vietnamese pronunciation.
[1] According to a 2013 study, it was the 25th most-common name, shared by 9,170,000 people or 0.690% of the population, with the province with the most being Hunan.