The Anti-Mui Tsai Society was an organisation founded on 26 March 1922 dedicated to abolishing the Mui-tsai system (akin to child slavery) in colonial Hong Kong.
[2] The system was a traditional Chinese custom that existed from the foundation of British Hong Kong in 1841.
The Anti-Mui Tsai Society marked the increasing social activism of Chinese Christians and labour unions in colonial Hong Kong.
This made it necessary for Britain to address the Mui Tsai system, and the issue attracted international attention.
After strong political pressure, the Hong Kong authorities introduced the Female Domestic Service Ordinance in 1929, which prescribed that all Mui Tsai-girls were to be registered by 31 May 1930.