This paper presents an innovative gear-driven rotation-amplified rubber viscoelastic damper (GRRVD) to reduce the seismic shift responses of beam-column connections in frame structures. Based on the principle of gear transmission, the damper can amplify the rotational deformation of the beam-column joints of frame structures according to actual engineering needs and give full play to the energy dissipation capacity of rubber viscoelastic materials. First, the design philosophy, basic construction, working mechanism, and outstanding features of this damper are introduced. Then, cyclic loading test is carried out to study the influence of rotational deformation and loading frequency on the mechanical properties of the fabricated GRRVD. Additionally, a mechanical model which can precisely simulate the hysteretic characteristics of the damper is derived and then verified by numerical simulation. Finally, a nonlinear time history analysis is performed on a six-story steel frame for three cases: no dampers, dampers without deformation amplification, and dampers with deformation amplified by a factor of 2.5. The results show that the control effect of the damper can be improved by two to four times by amplifying the rotational deformation response at the beam-column joint by 2.5 times. K E Y W O R D S beam-column joints, passive control, rotational deformation-amplified damper, seismic response analysis, theoretical model 1 | INTRODUCTION Earthquake hazards and wind disasters have been causing enormous losses to human life and society. 1-5 Protection for civil engineering structures from the damage due to earthquake or strong wind is a critical issue. Various measures have been developed and implemented to reduce excessive structural dynamic responses, such as active, passive, hybrid, and semi-active control methods. 6,7 Passive control system is to dissipate seismic energy through the energydissipating devices attached to the structures. 8 Due to its simple construction, low cost, convenient maintenance, and no external energy requirement, the devices (or dampers) have been widely used to mitigate the dynamic response of building structures. 9-14 However, the seismic damage of frame structures is mostly concentrated in the area of beam-column joints, and the performance of joints has a significant effect on the overall safety and stability of the whole structure. 15-17 When the