The purpose of this study is to detect systematic side of Abu Ammar Abdul Kafi through the following points -Definition of Abu Ammar and his scientific efforts, and the study of the time in which he lived includes scientific, political and economic features and to presentation the effect of that. - The general approach which was followed by Abu Ammar in the division, classification, language and style. Whether in his statement, educational or dialectical in his speech with violators, the study showed the effect of the book In terms of methodology in classification, and in terms of the issues raised and discussed . -Comparison between the Al-Mujaz and the famous previous Abadi work books, to present the status Al-Mujaz of the methodology in terms of classification and in terms of the issues raised and discussed . -Exploration of the issues on the side of Theology and classified considerations. In terms of source of inference to text inference and mind inference. •In terms of the rules and regulations adopted by Abu Ammar to discuss the issues. • In terms of proving the case and understanding of the issue and on this Abu Ammar was dependent on the text. •In terms of the rules in verbal reasoning. -Characterization of the logical trend which was followed by Abu Ammar. The most important finding by the study: -The study revealed something of the ethics of the scientists working given to Abu Ammar, for example, the accuracy of transport from the violator, and impartiality the violator, and accuracy in the dialogue and the good manners in conversation, it is degree not occupy of him degree in theology that loves controversy and fight the opponent, what was known about him from the positions shown interest in working more than say. -The study showed that Al-Mujaz latest quantum leap in authoring of West Ibadhi and it was marked by a number of features, including: in the way of authoring and regulation in the tab, and it was the most previous books that take care of inference and evidence put forward and discussed. - Dimension inferential of Abu Amar, by presenting some evidentiary controls ,or through the handling of the cases, has been adopted on the Koran as a source to prove the case doctrinal only