Abstract: Some changes of structure and properties of cyanate ester (CE) resin and its composite before and after dynamic mechanical analysis(DMA) were studied by fourier transform infrared(FT-IR), thermogravimetric differential scanning calorimeter (TG-DSC) and dynamic mechanical analysis (DMA), and the effect of DMA test on structure and properties was investigated. The results show that the force was the main factor to influence the structure of CE resin and its composite at high temperature. The high temperature during DMA test could make CE rein solidify further, thus to increase the storage modulus of resin and its composite. The interaction of high temperatures and force made the segment distributing of the pure CE resin broadened and the damping peak of the interface phase and the matrix phase of the CE/ZrO2 composite fused.