Each branch of humanity sciences must have its own terminology، which differ from others according to plain method in which its vocabulary must be interpreted and explained ، eventually this vocabulary must form specific comprehensive definitions ، which has its rules and codes as we defined "limits" . The following research aspire to define the readers with the critical awareness features of grammatical limits ، where handles through two levels: The first level ،through its studies، covers the authority of the idiom and the bases of the human studies ، then turns to prescribe the grammatical limits ، then he looks for the elements of its growing up، and throws light on the aspects of its development by our important ancient grammatists . Whereas the second level completes and promotes the first with practical examples in which it evaluates the efforts the Arab grammarians exert in building limits in their grammatical terminology .it shows the aspects of the renewal in its industry according to the objective rules and scientific condition limit building depends on . Thereby to seal the most important research results .