Abstract: The wettabilities of anthracite, manganese sand and quartz sand particles with a size range of 0.9—1.2 mm were compared using the Lipophilic Hydrophilic Ratio(LHR) concept which was defined on the basis of the Washburn equation, and their surface free energy components were also estimated using the Washburn equation and van OssChaudhurryGood(vCG) theory with n-hexane,α-monaphthalene, formamide and water as probe liquidsThe calculated LHR values of anthracite, manganese sand and quartz sand were 1.93, 0.75 and 0.69 respectively,showing that anthracite was lipophilic comparatively while manganese sand and quartz sand were hydrophilicFurthermore, the estimated surface free energy apolar components and polar components of anthracite, manganese sand and quartz sand were 38.8, 38.0, 37.7 mJ·m-2 and 0.73, 6.8, 8.7 mJ·m-2,showing that the wettabilities of filter medium were correlated to their surface free energy polar components; and the latter could be ascribed to the differences in surface chemical structure of different filter medium.