Under a collaborative project between China and UK partners, investigation was carried out on high-sulphur coals from Beisu Coal Mine in Shandong Province and Dizong Coal Mine in Guizhou Province to evaluate the sulphur reduction potential by coal preparation. Extensive evaluation of raw coal samples was carried out for design of optimum sulphur reduction processes. This paper discusses the background to the project and describes the evaluation process. This involved selection and sampling of the coals, determination of their washability characteristics and application of process prediction models to the washability data to assess their sulphur reduction potential. This paper demonstrates the potential of model predictions for the development of optimum desulphurisation processes using latest separation processes and plant design. The study has shown that over 50 wt% of sulphur can be removed from Beisu coal (ash 17.9 wt%, sulphur 4.8 wt%) and over 60 wt% of sulphur from Dizong coal (ash 33.5 wt%, sulphur 5.1 wt%) using latest coal cleaning processes.