Abstract: Based on the basic theory of structural dynamics, the determinationof damping coefficients of pavement materials and itsinfluence on the dynamic deflection of asphalt pavement were studied. Theresults demonstrate that the damping coefficients determined from the naturalfrequencies of the first and second principal vibration modes do notsuffer from theerror of the conventional calculation method. The viscous dampingcoefficient has little influence on the pavement deflection and can beneglected in the dynamic analysis of pavement structure. Compared with theother materials, the damping feature of the subgrade is a main factoraffecting the pavement deflection. The analysis provides a reference forthe calculation and determination of material damping coefficients in dynamic analysis of pavement structure.