This study, entitled “Sentence Structure in the Book of Al-Luma'a’” by Ibn Jinni, a study in the grammatical language, striving from our humble endeavor in our field of specialization by reviewing our Arabic grammatical linguistic texts in search of a phase of the Arabic language in its grammar and sentence construction in the fourth century AH, to represent a small nucleus of a large ambitious project. Our choice fell on one of the grammatical abbreviations written by the great linguist Ibn Jinni (392 AH), I mean the book (Al-Luma’a in Arabic), which, despite its importance as evidenced by the many explanations, had an educational character. In it, Ibn Jinni used a simplified language that is close to understanding and comes close to the intermediate Arabic language, or perhaps What was spoken at that time. We have taken this book as a model, in order to clarify the steady trend that took place in the Arabic language in the first half of the fourth century AH, through the construction of its sentence, as (the sentence) the smallest linguistic unit of speech, the subject of grammar and its scope. The study focused much attention on the applied aspect. The study's questions are based on a fundamental question: How did Ibn Jinni built his lengthy nominal sentence in his book Al-Lama'? Two questions branch out from it: The first is: What are the regular structures or patterns that form its lengthy nominal sentence? Then what patterns were less consistent than their counterparts? As for the study’s approach, it is a descriptive approach based on extrapolating the structures of the lengthy nominal sentence in Kitab al-Luma’, the structures that Ibn Jinni employed to present its grammatical chapters and its scientific demands, and then classifying them to identify the patterns in them, whether they were dominant or small in his opinion, or perhaps those that did not exist in him. The classification process appears in the research in the form of tables dealing with the structures and patterns of nominal sentences that are excluded first, then those that are not.