Abstract: Pore structure of Chinese coals with various ranks was characterized with three analytical methods (carbon dioxide adsorption, nitrogen adsorption, mercury method), and its effect on the properties of coal water slurry (CWS) was discussed. The results indicate that there is less correlativity between the pore structure and the properties of CWS. Different slurryabilities of CWS are found for coals with similar pore volume and pore size distributions. The properties of CWS is dependent on not only coal pore structures itself but also the surface features of physical chemistry such as the content of oxygencontaining functional groups , coalwater contact angle and the moistureholding capacity of coal.