Wind-induced vibration of tall buildings have been of interest in engineering for a long time. Wind-induced vibration of a tall building can be most effectively controlled by using passive control devices. The tuned liquid damper(TLD) is kind of a passive mechanical damper, which relies on the sloshing liquid in a rigid tank. TLD has been successfully employed in practical mitigation of undesirable structural vibrations because it has several potential advantages: low costs, easy installation in existing structures, and effectiveness even against small-amplitude vibrations. Shaking table experiments were conducted to investigate the characteristics of the shallow water sloshing motion in a rectangular tank. To increase the damping ratio of the rectangular water tank, triangle sticks were installed at the bottom of water tank. This installation increased the damping ratio by amaximum of 40-70%.