The paper is devoted to the analysis of complex sentences with subordinate clauses of condition, cause, goal, concession, consequence in regional newspapers of Kostroma Region in comparison with the data of similar studies conducted on the material of all-Russian periodicals. The grammar of the language, which is the backbone of the entire language system, is the most stable, standardised, which should be manifested at the syntactic level. The description of linguistic phenomena in the materials of regional periodicals in comparison with the all-Russia’s ones contributes to the forming of a general picture of the syntax of the modern Russian language. This paper shows on quantitative research data the correspondence of the syntax of regional newspapers with the language of all-Russia’s periodicals in the following aspects – the distribution of complex sentences with various types of subordinate clauses in the general system of conditionality and the peculiarities of using the means of their construction. It is shown that in the texts of regional newspapers of Kostroma Region, at the syntactic level, there are all the structural and semantic features of complex sentences with the meaning of conditionality – distribution by their types, the use of typed and non-typed means of communication, the phenomena of gradation, inversion, parcellation, phraseologisation of subordinate clauses. On the example of functioning of the most popular, semantically capacious and significant complex sentences, it is concluded that the syntactic media image of Kostroma Region reflects the general picture in modern Russian journalism, which indicates the stability of the system of complex sentences at the current stage of language development.