Persian metres are in the form of quantitative-syllabic metres, which only relied on this feature, created more than 400 pleasant metres. Classification of "Persian metres" is one of the categories that has not yet been fully liberated from the traditional cumbersome rules of worship. The “New prosody” with people such as Khanlari, Farzad and Elwell Sutton took steps in this regard; but the mistakes made by each of these people and the lack of clear and scientific rules failed to completely eliminate traditional prosody. After many years, Abulhassan Najafi has been able to explain the results of his many-year research, which has become part of a paper and article, as a method for classifying Persian metres, which, of course, was not perfect. This research pursues two main goals. One is related to the critique of Najafi's work, in terms of both efforts and inventions, and weaknesses and landslides. Another goal is to introduce a new classification that, taking into account the inherent characteristics of Persian language and poetry, has a regular and basic system, so that it has several functions as fallows: a) it identifies the greatest number of metres; b) helps us easily to find the metre of its scansion and pillars(metrical feet); c) Properly illustrates the structural characteristics of each metre and metres of its family; d) For the metres that probably will add in the future will provide a good place. Najafi's efforts can be examined on two axes; one section relates to his exact and scientific pathology on the erroneous classifications of each of the past prosodists. The other part relates to the importance of the circle attributed to him, which is of course the innovations of Iranian prosodists, and referred to in Miyar Al-Ashar and Al-Mu'jam. The significance of the Najafi's circle and its corresponding table is that the 31 most popular Persian metres, which accounts for 90% of Persian poems based on their metres, is easily justified. This means that by scanning each of these metres and re-pillaring them, according to the formulation of this table (and contrary to what has been pillared in the traditional prosody), one of these metrical families can be obtained, either in accordance with the metre of the head group or one of the subgroups. The greatest Najafi slip can be seen as a failure to justify part of the pleasant metres that are beyond its circle, especially the 14 metres of the total metre of Simin Behbahani. To achieve a comprehensive classification of metres, the second goal of this research, we have introduced five weight categories: 1. Frequent metres, 2. Alternative metres, 3. Cyclic metres, 4. Broken metres, 5. Caudate-like metres. Each of these categories has a special form and consequently its own characteristics and is divided into subordinate metrical families. Each metrical families consists of a combination of two metrical feets, which are composed in the form of that category. Ultimately, syllable reduction method is used to reach other members of the family. For example, if we consider this metre, “mafā`ilun fā`ilâtun mafā`ilun fā`ilâtun”, then its analysis will be as follows: a) the metre is alternative; b) is the head of the “mafā`ilun fā`ilâtun” family; c) the root of this metrical family is made up of “mafā`ilun” (Four-syllable feet) and “fā`ilâtun” (the other Four-syllable feet); d) Another member of its family is “mafā`ilun fā`ilâtun mafā`ilun fā`ilun” which is obtained by syllable reduction method
