In traditional China, the emperors always divided their people into different social classes of different statuses of law according to their social status, professions and so on. Apparently, it was a hierarchy of social order. After the Han Dynasty, especially from the Tang Code to the Great Qing Legal Code, slaves were ranked as untouchables. The names of slaves were diverse. In the Tang Dynasty, for example, they included Puchu（部曲）, Kenu（客女）, Yuehjen（樂人）, Tsahu（雜戶）, Kuanhu（官戶） and Nupi（奴婢）. In the Qing Dynasty, the intellectuals, farmers, workmen and businessmen were included in upper social statuses, and Nupi, Changyu（娼優）and Litsu（隸卒）were in a lower class.