Abstract: Super typhoon Haiyan (2013) was the most notable typhoon in 2013. In this study, the operational prediction of Haiyan (2013) by the Tropical Regional Model for South China Sea (TRAMS) is analyzed. The results show that the model successfully reproduces Haiyan 's fast passage through the Philippines, and its northward deflection after landfall in Vietnam. There are also some shortcomings, including the predicted too weak intensity compared to the observed. An analysis of the higher-resolution model simulations indicates that the storm is also characterized by an upper-level warning core during its mature stage, and a deep layer of easterly flow. Sensitivity experiments are conducted to study the impact of certain physical processes on the improvement of the typhoon forecast. The results show that appropriate boundary-layer, cumulus and orographic gravity wave parameterizations, and improved initial conditions as well as increased horizontal grid resolution all help improve the intensity forecast of Haiyan.