The first studies, whose authors were systematically trying to develop the theory of Slovak and Bulgarian phraseology, followed up the theoretical work of former Soviet Union linguists in the second half of the previous century. The phraseology investigation in Slovakia and Bulgaria has moved into a new phase in the seventies of the previous century. The new phase is characterized by effort to bring modern and systematic phraseology description as the independent scientific discipline. Both phraseology schools differ mainly in having an opinion on the subject of phraseology. On one hand in Slovak phraseology wide criterion theory is accepted, on the other hand majority of Bulgarian phraseology scientists respect more or less restriction criteria in relation with the subject of phraseology. Bulgarian phraseology theory has to respect common language and grammatical peculiarities of Bulgarian language.