Over the years, archivists of Tatarstan have been studying this manuscript of Sibawayh’s Kitāb. The history of its appearance in the Kazan Theological Academy still remains unstudied. The first scientist who started the scientific study of the Kazan fragment of this manuscript was Doctor of Philological Sciences, Professor of the Institute of Oriental Studies of the Russian Academy of Sciences in Saint-Petersburg A. Khalidov. The scientist, having collated the folios with other manuscript reproductions kept in the Cairo Manuscripts Institute of the Arab League, dated the Kazan fragment to the late 12th- the early 13th century. In the following years, the studies of the manuscript continued. So, in 2009 a French scholar, Dr. G. Humbert, who had written her Ph.D. thesis on the manuscripts of Sibawayh’s “Kitāb” (Paris, 1992), identified them as belonging to a codex found in the Ambrosiana Library in Milan. G. Humbert in her conclusions dates the manuscript before the middle of the 11th century. In February 2018 the author of a codicological study of the Milan fragments of the manuscripts U. Bongianino draws attention to six folios of the codex that were on sale in London in the catalogue of Bernard Quaritch Ltd under the number 11. The above-mentioned and the Kazan folios belong to the same codex and the same conclusions generally apply to them. Both fragments are entirely written on parchment but the state of conservation differs. The Milan fragments contain only slight defects but the Kazan fragments bear water stains, burnt or missing parts of texts. By the time of writing the article on the fragments of Sibawayh’s manuscript, the study contains information on its complete textual sequence, dimensions, and paleography. So far only 25 % of the text has been found, the collection of the data on 75 % of the rest text is still going on and any findings of the research should be considered provisional. A more comprehensive study of the history of the spread of the fragments and the answer to many unstudied questions are required. The Kazan fragments of Sibawayh’s manuscript are an invaluable asset, both as a cultural object and as a witness to the vivid history of the Arabic grammatical tradition in the early centuries.