The aim was to study seasonal snow and permanent snow variation in alpine regions using coherence component data derived from a multi-temporal of PALSAR InSAR data. With coherence decomposition technique, we obtained the multi-temporal data of temporal-coherence component near Mt. Dagu, China, where vegetated surface, seasonal snow cover or grazing area, and permanent snow cover exist. The variation of temporal-coherence component through time indicated changes of snow cover and status within the grazing zone and permanent snow area or areas above tree line. After the analyses of the temporal-coherence components from January to February, February to April, April to May, and January to May of 2008, we were able to identify snow status and change of snow cover above local tree line. The overall accuracy level greater than 71% was achieved in the identification when compared to those derived from multi-temporal TM images of Landsat 5. The results were promising.