The article discusses the problems associated with the definition of the relations between the Russian Orthodox Church with schism and sectarianism which received the active development in the second half of the XIXth century in Kazakhstan. According to the analysis of a large amount of archive data it is established that this relations had tight constitution. The Russian Orthodox Church used all available methods and tools aimed at the struggle with the Old Belief and sectarianism. The main mission of this struggle was to spread missionary work among dissenters and religious and moral propaganda among the Orthodox population to prevent their transition to schism.

Key words: orthodoxy, Old Belief, sect, Russian Empire, Kazakhstan, missionary work.