This thesis has dealt with a study of AL Muaddib's (DAQAE'Q AT'TASREEF). It investigated the grammatical terminology in the book, the grammatical issues, and the sources this author used in his writings. This study relied on a descriptive and analytical approach as required in a way that showed the scientific approach this author used. The research is divided into 4 chapters with an introduction and a conclusion. The introduction stressed the significance of the topic, the rationale for the choice of this topic, and the research methodology. The four other chapters are as follows: - Chapter One: The grammar terminology in AL Muaddib's (DAQAE'Q AT'TASREEF). and is divided into two parts: First part: the grammatical terminology in the book between Alkofieen and Al Basrieen. The second part: AlmuAddib's grammar terminology. - Chapter II: Noun Issues and includes 13 issues. - Chapter III: The verb issues in the book and includes (20) issues. - Chapter IV: The sources of Almuaddib's grammar research and is divided into the two parts: First part: The scholars he relied on in his research. The second part: his proof. - Conclusion: highlights the results.