We investigate capability to detect the growth stage of paddy rice using full polarimetric L-band Synthetic Aperture Radar (SAR) data. The study area is paddy fields surrounding Field Science Center (FSC), Tohoku University, which is located in the northeastern part of Japan. The data are multitemporal, observed by Phased Array type L-band SAR (PALSAR) mounted on Advanced Land Observing Satellite (ALOS). SAR data are decomposed by Cloude-Pottier (H/α/A), Freeman-Durden, and four-component scattering mechanism decomposition. At the peak of plant height, the anisotropy values also peak and the alpha angle values range about 45°. At the same time, the relative contributions of double bounce component decomposed by both of Freeman-Durden and four-component decomposition increased by about 20% compared to seasons when plant height is lower. Double bounce scattering component appears to increase with rice growth. In addition, the parameters for Cloude-Pottier decomposition are helpful to clarify scattering mechanism at the target. These characteristics are different from the analysis results of RADARSAT-2 that are processed in the same way. PALSAR data are supposed to detect the growth stage of paddy rice more clearly than RADARSAT-2.