Interseismic deformation describes the gradual accumulation of crustal strain within the tectonic plate and along the plate boundaries before the sudden release as earthquakes. In this study, we use five years of high spatial and temporal geodetic measurements, including Global Navigation Satellite System (GNSS) and Interferometric Synthetic Aperture Radar (InSAR) to monitor 3-dimension interseismic crustal deformation and horizontal strain rate in Taiwan. We find significant deformation (strain rate > 8x10^-6 yr^-1) along the plate boundary between the Philippine Sea Plate and the Eurasian plates in east Taiwan. The high strain rate in the southern part of the Western Foothills is distributed along a few major fault systems, which reveals the geometry of the deformation front in west Taiwan. Our results help identify active faults in southwest and north Taiwan that were not identified before. These findings can be insightful in informing future seismic hazard models.