Moisture transfer in building components and furnishings has a significant effect on indoor humidity and latent cooling load. M any mathematical models and calculation methods have been proposed to evaluate this sorption effect . Which is actually simple and accurate as well? The result from the discussion in this paper shows that the one-dimensional linear moisture transfer model in which vapour pressure is as only driving potential is both quite simple and in conformity with the situation. The frequency analysis shows that the model of surface moisture sorption and its transfer function method are the simplest and have an appreciate accuracy. The moisture interaction depth should be accurately determined in this model to reach a hither accuracy.