Presently, interlocking mortarless masonry system has been developed as an alternative to the conventional mortared masonry system for wall construction. This book presents numerical investigating for structural response of interlocking masonry system using finite element method. Program code for modelling and analysis is developed incorporating appropriate mathematical models to simulate the main features of mortarless masonry system. These models are obtained experimentally using small scale specimens. The main features simulated are the nonlinear structural characteristics of interlocking dry joints and masonry materials under different loadings. The results indicate that the developed finite element code can successfully trace the structural behaviour (capacity, deformation and mode of failure) of the interlocking mortarless masonry system from the initial stage of loading till failure. A general equation is proposed to estimate the capacity of the interlocking mortarless masonry walls under eccentric and concentric vertical loads. The equation can be easily used for structural design of the masonry system.