Ongoing crustal deformations in the active arc-continent collision of Taiwan generate large amount of deformation and therefore pose potential seismic hazards as well as risk to infrastructure on the island. In this paper we used radar image pairs with long time span and large area of coverage in order to investigate deformation over the western Taiwan in large spatial and temporal scale. Pre-seismic, co-seismic, post-seismic, and inter-seismic deformation patterns are spatio-temporally analyzed. These areas of interest are located in the Western Foothills of Taiwan orogeny, which the deformation front of the mountain building is propagating toward. In order to better approach the problem, we classify the crustal deformation into intense and gentle events reflecting different deformation styles. Three case studies of deformation events using DinSAR images will be reported. They are: the co-seismic deformation associated with the Chi-Chi earthquake, uplift of the Tainan area, active deformation of Chinshu fault. Correlation of location and time of these deformations is analyzed to investigate the possible precursory to a major earthquake and better understand dynamic rupture mechanisms.