This paper presents a polarimetric SAR interferometric SAR data analysis based on ESPRIT algorithm and three-stage inversion algorithm. The formulations of ESPRIT algorithm and three stages inversion algorithm are presented firstly. The experimental results based on ESPRIT algorithm and three-stage algorithm have been compared and analyzed then. And we point out that direct conversion of the retrieved height of the scattering center corresponding to a single polarimetric channel to the forest height, will lead to underestimation. Therefore, it is important for the conversion to be carried out on the basis of a coherence scattering model of forest, which expresses radar observations in terms of a small number of vegetation and underlying-surface parameters. The experiment data is from PolSARpro software at L band.