This report presents the results of the experiments on the influence of high-frequency and wood structure to the dielectric properties of Paulownia wood.The results show that the effect of frequency on loss tanδ is big, but small on dielectric constant and resistance; the effect of wood density on dielectric properties is small, It is Suggested that good heating effect with low energy comsumption can be obtained by using the frequency at max./min. loss tanδ.