Two kinds of tsunami models are used in this thesis to simulate tsunami propagation in the ocean. One is the linear dispersion tsunami model developed by Port and Airport Research Institute (PARI), Japan. The other is COrnell Multigrid COupled Tsunami model (COMCOT) developed by the School of Civil and Environmental Engineering, Cornell University, that carries on the tsunami run-up computation to the nearshore region. Two kinds of tsunami models have the same mechanism of initial wave profile, which is the vertical seabed displacement as the initial tsunami profile proposed by Mansinha and Smylie (1971). Both models describe the tsunami by the same shallow water equations. At first, the feasibility of the PARI model is established by comparing with the record in Maldives during the South Asia tsunami in December 2004. Then, the COMCOT model in applied to the Pingtong earthquake in December 2006 and is validated by comparing with the tidal station records. Possible submarine fault activities around Taiwan and the Western Pacific ring is simulated by the The PARI model based on moment magnitude scale (¢Ûw) close to the South Asia tsunami. Seven sources are chosen: the Hokkaido, the East Japan, the Ryukyu Islands, the Guishan Island in Taiwan, the Fukien of mainland China, the Luzon Island and the New Guinea. The results suggest the northeast and southwest part of Taiwan have potential tsunami risk. Finally, we simulate the fault activity between Taiwan and Luzon islands by the COMCOT model. The inundation area extends northward to the Tso-Ying and San-Min districts, eastward to the Siao-Gang district and Fengshan city. The Kaohsiung harbor can resist tsunami hazard for moment magnitude scale (¢Ûw) up to 7.58 with maximum wave height of 5.5 meters.