Diyarbakır Great Mosque is a community building located in the district of Cami-i Kebir in the northwest of the traditional city area surrounded by walls. The building on Gazi Street opposite Hasan Pasha Han is inside the road, and the eastern entrance overlooks a square which very likely corresponds to the old forum of the city of Amida. Surrounded by the streets to the North and West, the South overlooks the traditional Sipahi Bazaar. Around the full court near the square of the building, in the south there are: Hanafis section, Shafis section, northern vestibule, Mesudiye Madrasa and its southern portico, a traditional house, and a lavatory. To the east, there is a library, which used to be apparently a timing room (muvakkithane) and an entrance to the East (Eastern Maksurah). To the west, in the Western portico (Western Maksurah), that also includes the Western entrance, there is a Qur'anic school. The octagonal and pointed pyramidal coned fountain, built during the Ottoman period, and the prayer hall and pool, which were raised with several steps, form the other units in the spacious courtyard. In the north of the courtyard, we can find the portico of Mesudiye Madrasa. There is also a solar clock in front of the northern vestibule. The aims of this study are: ● introducing the excavations in the Diyarbakır Great Mosque Western Maksurah and explaining the reasons of these excavations; ● presenting the results of these excavations; ● giving information on the excavation findings; ●explaining the importance of research excavations in restoration works. The evaluations made for the preservation of the excavation findings, which were deemed necessary during the restoration works in the great Mosque, will also be explained in this study.