ABSTRACT: Masonry is commonly used in the construction of traditional Japanese castle before and it is expected to be applied to retaining wall construction. Hence, the study of mechanical behavior of the masonry is necessary and only discontinuous based numerical approach can detect explicitly. In this research, a field experiment was held to detect the behavior of a masonry retaining wall under static load and a numerical simulations using Discontinuous Deformation Analysis (DDA) was carried and compared with the results obtained from field experiment. The simulation of masonry’s behavior such as deformation mode and displacement was similar to the ones obtained from the field experiment. The DDA simulations clearly showed that the rocks at the center of masonry retaining wall were the most sensitive part when external loads were applied.