At present, the coach noise problem becomes more and more critical for China Railway High-speed (CRH) as the speed increases. The method of Operational Transfer Paths Analysis (OTPA) provides a fast and efficient mean to identify noise transferring path and evaluate noise sources contribution. The results of OTPA help improve the coach acoustic environment. This paper applies OTPA on CRH380B high speed train by considering aerodynamic noise as one major source for the first time, and the comparison of different noise sources contribution is achieved. According to analysis, the main contribution comes from bogie and roof.