This paper deals with a series of material test of mortar used for historical masonry structures such as Hagia Sophia, Istanbul. According to the historical documents, the mixing ratio by volume for the mortar is estimated as follows ; sand : slaked lime : brick=2 : 1 : 2/3. Mechanical characteristics of mortar such as compressive, bending and tensile strength, static and dynamic modulus of elasticity, experimental equation of estimating compressive strength are obtained. Young's modulus of mortar corresponds well to the one of the masonry used for Minarets determined by the micro tremor measurements.
