Chinese criminal procedure, the measure known as 'residential surveillance' was initially intended to serve as a relatively lenient, non-custodial coercive measure applicable in a relatively limited set of situations. Ultimately, however, residential surveillance has been retained in subsequent revisions of the Criminal Procedure Law (CPL) for its largely theoretical potential to reduce custodial detention and its more proven utility as a law enforcement tool. Consequently, the CPL 2012 has opted to retain residential surveillance in this dual and contradictory form that emphasises its role as an alternative to custodial detention while simultaneously legalising many of the measure's more problematic aspects. Looking back to the earliest legislative articulations of the practice of residential surveillance, it is clear that it was originally intended as a non-custodial alternative to arrest to be used in relatively limited circumstances. Residential surveillance was also sometimes used within factories or enterprises to deal with disciplinary matters that did not rise to the level of criminal offence.