Abstract: This paper focusecs on the coherent scattering model and parameter inversion algorithm of vegetation with polarization characteristics.Based on target decomposition theory, the relationship between complex interferometric coherence with height, extinction coefficient and topographic phase is quantitatively derived, and the extinction coefficient is regarded as a function of polarization components, so the coherent scattering model with obvious polarization characteristics is established. On this basis, considering the polarization dependence of model, full polarimetric interferometric coherence are used as input parameters, and then the vegetation height and topographic phase are retrieved by the three-stage method.Next, hard-in-loop polarimetric interferometric synthetic aperture radar (POLINSAR) system is constructed in anechoic chamber to validate the model, and a scene composed of araucarias and soil are measured.The experimental results show that the retrieval height is fluctuated 0.03m to the actual height when the ground-to-volume ratio is lower than-10dB, which validates the effectiveness of the model.