The characteristics of the freeboard combustion of Korean low grade anthracites were studied in two fluidized bed combustors, which employed over-bed feeding and non-recycle of cyclone captured solids. The total combustion efficiency was ruled mainly by entrainment of fed coal particles and more or less by the freeboard combustion of entrained coal particles. The conversion of entrained coal particles increased with the bed temperature and decreased with the higher coal feed rate per bed area.