Fluidised bed paddy drying using superheated steam is a newly alternative approach instead of using the conventional hot air. The mechanism of mass transfer for paddy drying in a range of initial moisture content between 25% and 44.5% d.b. is strongly controlled by internal moisture movement inside the kernel and a two-series exponential equation is suitably used to explain its movement. Drying parameters in the equation are a function of temperature and bed depth. For the paddy quality, head rice yield from the superheated steam drying is more sustainable and has higher values than those obtained from the hot air drying, whereas the colour of white rice becomes darker, making it poorer quality. The percentage of white belly is significantly affected by the initial moisture content. (C) 2002 Elsevier Science Ltd. All rights reserved.