The results of statistical experiments to find the characteristics of words that are traditionally considered as the Ohrid-Moravian and Preslav components of synonymous series – иерѣи ‘priest’ – жьрьць ‘priest, cleric’ – свѧщеньникъ ‘priest, clergyman’, колѣ- но ‘knee’, ‘kindred’ – племѧ ‘tribe, genus’, коньчина ‘demise, end’ – коньць ‘end’, кънигы ‘books’ – писаниѥ ‘scripture’, любодѣица ‘adulteress, fornicator’ – блѫдьница ‘harlot’ are presented. The use of information about the relative number of words in a subcorpus, about significant deviations from the average values, and the calculation of statistical characteristics of lexemes in each of the subcorpora made it possible, in particular, to detect opposed and non-opposed components of synonymous series. The methods used to identify the statistical characteristics of words have shown that the degree of opposition of synonyms can be different – statistically significant or statistically insignificant. On this basis, it is concluded that it is necessary to move away from the unconditional attribution of the components of the synonymic series to the Ohrid-Moravian and Preslav vocabulary: the relations between the components of each synonymic series are individual and can range from statistically opposed in the texts of different schools to