Abstract: A new type of liquid damper device-tuned liquid damper embedded a transverse cylinder (TLDETC) is developed and its damping characteristics is discussed in this paper. The additional sloshing damping ratio of TLDETC is obtained by combining the hydrodynamics theory and energy method, the optimal additional sloshing damping ratio is also discussed. Comparison analysis of damping characteristics between TLDETC and ordinary TLD are made through two setting schemes. Results show that the damping performance of TLDETC outperforms that of the ordinary TLD.