Аннотация:This paper attempts to apply the implications of the grammaticalization theory to the Russian prepositional system. Special attention is given to reconstruction of the grammaticalization path “nounpreposition” (example – evolution of Russian prepositional unit лицом к лицу с кем-чем ‘face to face with smth-smb’, ‘facing smb-smth’) and to design of a grammaticalization scale for 8 prepositional units including somatic noun глаз ‘eye’ on basis of their grammaticalization level determined.