Abstract: In order to solve the problems of which conventional crawler type tractor undercarriages are frequently apt to be vibrated and shocked, a new type of viscoelastic bogie suspensions was developed. The kinetic differential equation for the suspensions was established on the basis of complex stiffness theory, and its stiffness damping characteristics were studied according to the viewpoint of energy transformations. The static and dynamic characters of the viscoelastic materials were analyzed on the energy transformation rates for the suspensions. After the unit developed with viscoelastic bogie suspension was used in 240 kW crawler type tractors, its stiffness design curves were drawn up and its property analyses were carried out. Finally, property experiments were performed on an eletro hydraulic servo test platform for the practical products of the suspensions.