The main objective of the present study was to investigate the effect of the operating temperature (both sand bed and freeboard) and various chlorine additives (organic or inorganic) on the mass and elemental size distributions of heavy metal Cr, Pb and Cd during fluidized bed incinerasion, The results showed that higher freeboard temperature and additives of PVC, NaCl, and CaCl2 appeared to shift the particles to a finer distribution. The addition of NaCl is more effective in reducing particle size as compared to increase the freeboard temperature or the addition of PVC owing to its mechanism of reduction in particle size. The metal concentration of size segregated coarse particles (5-125 mu m) are irregular. But in fine particles (0.1-15.72 mu m), the concentration of Pb, Cd is higher in the finer particles.