The city of Tanis is one of the most important cities in ancient Egypt. It was the northern capital of Egypt and the royal headquarters of the kings of the twenty -first and twenty -two dynasty. It is in the east of the Delta, about 150 km northeast of Cairo, on the ancient Tanis branch of the Nile. The Royal tombs of Tanis was discovered by the French archaeological Pierre Monte in 1999. The material building materials are currently suffering due to many aspects and factors of physical, chemical, biological, and human damage, such as the deterioration and loss of many stone blocks, binding mortar, and decorative units, accumulation of dusts and cracks that are varied in shapes and sizes in the painting, crystallization of salts on the surface and between layers, which led to the separation, fragmentation and peeling of the stone surface and the disappearance of many decorative elements, scenery and colored relives. Therefore, the research aims to study the materials for building tombs to find out the most important physical and chemical changes that occurred to them and led to their deterioration in preparation for the development of a scientific plan for the restoration and conservation of these tombs and their decorative elements. The components of the tombs were studied through investigation and using various analysis methods such as X-Ray Diffraction (XRD), Scanning Electron Microscope with Energy Dispersive X-ray (SEM-EDX) analysis of elements, Polarizing Microscope (PM). physical and mechanical properties of the stones used in the construction of graves were carried out. The results The results indicated that, the tombs were constructed using blocks of restricted limestone and were linked with a mortar of Gypsum, sand and stone powder and used some granite pieces in the doorstep over the entrances, and the main reason for the damage of building materials is a group of natural factors, the most important of which is rain water, the ground water and the various salts it contains due to the low location of the tombs within the archaeological hill and the proximity of the archaeological hill to the salty water sources represented in Lake Manzala, agricultural lands, waterways and agricultural banks.
