Most scholarship in colonial history has focused on law as an instrument of imperial domination, and colonial Korea is no exception. In Korean historiography, the view that legal changes that took place under Japanese rule were essentially geared to promote imperial interest remains predominant. Many scholars have focused on the question of the suppression and distortion of traditional Korean law and legal system by the arbitrary imposition of foreign law, but it leaves unresolved the problem of how to evaluate the emergence of Korea's postcolonial legal order. My study focuses on the colonial construction of customary law and its impact on modern Korean civil law and jurisprudence, seen from a comparative perspective of colonial law in the early twentieth century. Following Korea's annexation by Japan in 1910, the colonial authorities imposed Japan's civil law as the general law in Korea, but decreed that most private legal relations among the Koreans be governed by Korean custom. Because Chos┼Ćn Korea did not have a body of private law, the formulation of customary law was entrusted to judges and legal scholars who ascertained and interpreted Korea's customs through Western concepts of legal rights. Colonial courts persisted in the belief that customary law derived its validity from past popular behavior but the judges in reality treated custom as a mere persuasive basis for a judgment, substituting for the authority of custom the general principles of law. Legal machinery of custom fostered an atmosphere akin to judicial activism in the common law traditions, and it subsequently influenced postcolonial Korean jurisprudence with its heightened conception of judicial mission to create a modern private law system.