Abstract: For three hollow columns of non-obstructive particle damping, the influences of factors such as particle filling ratio, mass ratio, structural configuration of cavity and particle material type etc on the damping characteristics of columns are investigated by free vibration experiments, using iron powders, lead powders and sand grains as filling particles respectively. The reasonable structural configuration of cavity is explored. Test results indicate that the particle filling ratio and the mass ratio are principal influencing factors for the damping of columns and that maximum effect of damping improvement for columns may be obtained by rational choice of mass ratio or filling ratio in designing non-obstructive particle damping columns. In addition, the application of multicavity configuration and multicavity particle filling scheme, and the adoption of suitable material type of particles are beneficial to the damping enhancement of columns. No matter metal or nonmetal particles are adopted, the mass ratio should be controlled at a range of 0.3 to 0.5. If only small amount of particles is filled, higher structural damping can be acquired by using metal particles such as lead powders and iron powders than by using nonmetal particles. The experimental results may provide the basis for the rational design of non-obstructive particle damping columns.