Generally, the walls of ceramic ware are thin and the sample to be used for TL dating has to be collected from 1~2mm under the surface. This can introduce significant error into the dating method. Therefore, the results of a series of simulated experiments are reported on the build-up effect of the internal β dose response in different thicknesses of pottery fragments (involving tile and brick). Correction factors, corresponding to different thicknesses, and correction "depths" are proposed in terms of the experimental findings which may be incorporatd into the dating methods.