Dominance is one of the most vital and creative key terms which bounds up with the linguistic approach to formalism. According to critics’ definitions, “Dominance” has the potential to govern the elements of structure.  It is palpable to that the consistency of structure and coherence is indebted to “Dominance” so that we can argue that  comprehensiveness of this element is a kind of guaranty for understanding the elegancy of form and structure of poems. This dominance rules over other elements of language poetry and locates them in the right position. We can maintain that  “dominance” emerges in the exterior aspects of structure through symbols, repetition of lines, and mottos, proverbs, and other kinds of repetition. Furthermore, “Dominance” has some crucial functions which are extremely imperative for recognizing external aspect of pomes. To enrich the orchestration, making a skeleton for structure, monotone, fragmentation of structure, open end ness of poem, reasonable the verse and another important function. In this article, the functions of Dominance which is an essential element in the surface of contemporary poetry in Iran, will be fully discussed.