The present study is devoted to the analysis of the legal background of the laics associations emergence and activity in the Kiev mitropolia in the second half of the XVI century, including church, parish and “honey” brotherhoods, guilds and collective patrons of orthodox churches. The aim of the work is to assess the nature and degree of secular and ecclesiastical legislation influence on the emergence and methods of legitimization of Orthodox religious associations in the second half of the XVI century. The church brotherhoods of the end of the XVI century were the result of the evolution of traditional territorial unions that arose on the Ukrainian-Belarusian lands even before the adoption of Christianity. The factors of the evolution were the spread and deepening of Christian practices, and later the entry of orthodox lands into the catholic Polish-Lithuanian Commonwealth. The Western European legal system assumed the written consolidation of legal customs and legal facts. In the contact orthodox-catholic zone there were closely related catholic professional and religious unions of laypeople, whose statutory documents became models for copying. Finally, the third factor was the influence of the Reformation and Counter-Reformation, which provoked an increase in interest in the affairs of religion and the church among the orthodox laics and led to the emergence of church confraternities and confraternal movement. At the same time, the confraternal movement is a purely Orthodox phenomenon. Assessing the discrepancies between the church law norms and the confraternal ideology provisions, it should be emphasized that the confraternities rejected the norms that had the status of church custom, and in some provisions turned out to be closer to the canonical norm than the contemporary practice of the church.