Coastal vegetation is one of the important natural ecosystems that act as protection from sea wave erosion phenomena and supply oxygen to the surrounding organisms. POLSAR data with multi-band and multi-polarization is selected for these studies which are acquired on September 19, 2000 for coastal vegetation mapping. Two methods are performed to CVV, LHH and LHV bands: polarization signature analysis and comparison of classification between two clustering techniques (Fuzzy-k-mean and ISODATA). The result shows that L band with HV polarization can distinguish coastal vegetation better than CVV. Furthermore, classification results of LHH and LHV shows that the Fuzzy-k-mean clustering is provided accuracy of 76% and also with kappa statistic of 70%