As it is well known, the book of pslams has played a very important role since its first appearance in the Slavonic countries not only for the themes it deals with, but also for its didactic function. It has had huge diffusion in terms of place and time, and is therefore one of the few texts of Slavonic literature which has been able to reach now. From this point of view, the book of psalms provides great opportunities for linguistic research of the Old Bulgarian(or Old Church Slavic). The aim of this paper is to investigate the linguistic features of Psalm translation from Greek original text to Old Bulgarian. Analytic focus is concentrated on the lexical choosing and lexical diversity of emotional words in Psalm. The basic text for this research is Psalm in the Bible. For this purpose, the author has chosen for his work “The Sinai Book of Pslams(X c.) as the main text for comparative analysis with Greek original and another early redactions of Old Bulgarian Psalms, including Norov Pslams(XIV c.). On grounds of their different translation technic and choice of vocabularies, as well as the divergences in their Greek original, the author has proven the basic trends and principles of translation. For this study, the author has compared the emotinal words like joy, happiness, free will, hope, acquisition, exercise and transference of power, physical and spiritual suffering, sorrow, affliction in the Greek original text Psalm with its old Bulgarian version. And has found the most frequent translated vocabularies in Old Bulgarian text. They are as follows; (1) joy, happiness: радость, веселие. (2) free will, hope: хот□ти, жел□ти. (3) acquisition, exercise and transference of power: дръжава > кр□пость. > сила. (4) physical and spiritual suffering: бол□знь, скръбь. (5) sorrow, affliction: скръбь, печаль.