Various strong motion observations were widely deployed in Taiwan and collected a large amount of high quality earthquake data and provide useful information for seismology and earthquake engineering. These wealth ground motion data offer a good opportunity to study the attenuation models and the site amplification effects for a given site in response to different levels of excitation. The improvement of structural seismic design, which needs a proper definition of seismic demands for different site conditions, can efficiently prevent the damage of structures from the earthquake excitations and is the best way for earthquake hazard mitigation. We will presents an overview of the entire hazard analysis procedure and details the deliberations and decisions made in the determination of parameters for hazard analysis which includes: seismogenic zones, seismicity parameters, and attenuation and rupture length relations. Since the seismogenic zones used for the hazard analysis were based on the considerations of tectonics and past seismicity patterns in the region, the accuracy of the epicenters, focal depths, and magnitudes of Taiwan region needed to be investigated. Finally, the hazard curves and design earthquakes can be estimated for the seismic design of structures.