This research letter presents preliminary results of sugarcane mapping in its tillering period using quad-polarization data. Three TerraSAR-X images were collected in early, middle, and late tillering periods in the Leizhou Peninsula, South China. Polarization features based on Cloude-Pottier decomposition, such as scattering angle and polarization entropy, were used to analyze sugarcane scattering mechanism temporal behavior and the differences between sugarcane and other typical land cover types. Results show good separability of sugarcane from other land cover types. At last, based on common features of sugarcane in tillering period, a sugarcane mapping method was proposed with certain high accuracy and good stability. The results suggest that the tillering period, from early April to late May, is a suitable growth period for sugarcane mapping, and polarization features appear promising for crop mapping and monitoring.