Manuscripts are among the most precious treasuries left behind by our ancestors, and our duty is to protect and revive and introduce this cultural heritage. Although great attempts have been carried out, in the current era, to introduce these precious treasuries, there are still lots of manuscripts not yet identified and introduced. One of these unknown works is Bidel-e Dehlavi’s ‘Chahar Onsor’.In the present paper, the authors attempt to present the very valuable manuscript of Bidel-e Dehlavi’s ‘Chahar Onsor’ identified in the libraries of Iran .At first, we will have a brief look at Bidel’s life and manuscripts, and then investigate its content and literary value, then its different chapters are introduced, and finally, in common with the contents of manuscript lists, we cover the apparent characteristics of the manuscripts, such as the name of the author and scribe, the time and location of copying, number and size of the leaves and lines, and the beginning and end, the type of hand writing, and so on.The overall result of our research suggests that manuscript 2 of Tehran University bears more outstanding specifications compared with the other identified manuscripts.