This article examines the intertwined processes between China’s making of anti-slavery laws and the evolution of international legislation against slavery in the early twentieth century. By tracing international interventions into domestic servitude issues in Chinese communities both in China and Southeast Asia, the article analyses how the international legal regime was absorbed into the domestic laws of late Qing and Republican China. Drawing on two threads of scholarly discussion—namely, the histories of humanitarian internationalism and modern China’s legal reform—this article argues that late Qing and Republican jurists intentionally maintained an ambiguous definition of domestic servitude. This ambiguity served to affirm the humanitarian governance of the modern state while simultaneously preserving social customs, in defiance of international law.