Abstract: Two groups of multiple tuned mass dampers (MTMD) are used in a long-span lattice roof structure to reduce the vertical seismic reaction. The dynamic equation of lattice roof structure with vertical MTMD is presented, and the finite element model is established to perform dynamic time-history analysis using four ensembles of strong ground motion records. The paper also studies the correlation of vibration-dissipation of roof structure and frequency width, damping ratio, and mass ratio. Numerical results indicate the existing of optimum values of these parameters. The optimum frequency width is 0.2―0.3, the optimum damping ratio is 0.01―0.02 and the optimum mass ratio is about 0.005 considering the engineering practice. The spectrum characteristics of earthquake waves have little effect on these optimum values.