The TRACE (TRAC/RELAP Advanced Computational Engine) is a modernized thermal-hydraulics code developed by the NRC (U.S. Nuclear Regulatory Commission). It is designed to encompass all of the capabilities of RAMONA, RELAP5, TRAC-PWER, TRAC-BWR. The TRACE is able to analyze large or small break LOCA, accidents up to the point of significant fuel damage, and reactor transients in both PWRs and BWRs. The capability also exists to model thermal hydraulic phenomena in both 1-D and 3-D space. This is NRC's flagship thermal-hydraulics analysis tool. This paper is to build up the TRACE thermal-hydraulic analysis model of the Kuosheng BWR6 NPP (Nuclear Power Plant). The model is based on benchmark analysis against RETRAN analysis and the plant startup test data. The startup test is 100% power load rejection test. This test can provide valuable information for the benchmark studies of Kuosheng TRACE model. Furthermore the TRACE model can be applied to transient analysis and safety estimate in order to support the operation of power plant.