Damping double-tuned filters are widely used in the high voltage direct current（HVDC） projects， and damping resistors' selection plays an important role for filtering effect and performance of the whole system. Firstly， impedance frequency characteristic of the double-tuned filter with different damping resistors is compared and influence of damping resistors on the filter is analyzed. Then， taking the filter design of a±800 kV HVDC project for example， performance and steady rating results of filters under different damping resistors are evaluated. At last， the basic principles on selection of damping resistors based on performance and rating requirements are summarized， which effectively improve the efficiency of filter engineering design.