Noise barriers are widely constructed along railway tracks to reduce noise emission. The noise reducing performance depends not only upon the construction of the barrier but also upon the location of noise source and measuring point. As the multiple reflections take place between the barrier and car surface, we can not easily estimate the noise reducing effects of the barriers in the case of railway noise. In order to optimize the effects of noise barriers, therefore, numerical studies and experimental studies by using scaled models are carried out. This paper validates the relationship between field and simulation tests.