Somatic lexicon is an important part of the vocabulary of the Mari language. That is why it is important to investigate it to determine the historical development of the Mari language and to identify interlanguage and interdialectal lexical relations of the Mari language. Somatic terms of the Mari language, as well as other related languages, evolved over thousands of years. Somatisms considered archaic and resistant to changes by components lexical system of language. That is why it has always been used to solve many important problems in the history of the Mari language. This article describes one of the lexical-semantic groups of somatic vocabulary - the names of the human body bones. The totality of osteonymic vocabulary is divided into the following lexical-semantic groups: 1) the names of the bones of head, 2) the names of the bones of the neck and trunk, 3) the names of the bones of the upper limbs, 4) the names of the bones of the lower limbs, 5) the names of the skeletal system of human body as a whole.