One of the main R & D work in nuclear engineering is the development of computer programs related to nuclear power plant (NPP) safety analysis. The advanced thermal hydraulic code named TRACE for NPP safety analysis is developing by U.S. NRC now. Lungmen NPP is the first ABWR NPP in Taiwan and still under construction. The safety analysis of NPP is very important work. In general, the description and results of the safety analysis for the transients are in the Final Safety Analysis Report (FSAR) of NPP. In this research, the development of the Lungmen NPP TRACE model for the safety analysis is performed. The transient analysis prediction of the TRACE model for Lungmen NPP is also performed. The loss of feedwater flow (LOFW) transient data and MSIV (Main Steamline Isolation Valve) closure direct scram transient data from FSAR are used to compare with the predicted results of the Lungmen NPP TRACE model. The compared results indicate that there are the similar trends of parameters between the TRACE model of Lungmen NPP and FSAR for the analysis of the LOFW transient and MSIV closure direct scram (MSIVCD) transient.