The aim the present work is to investigate the possibility of using liquid fuel in a fluidized bed. The liquid fuel was injected into the bed by using a diesel engine pump and metal injectors which are used originally in diesel engines. The liquid diesel fuel was successfully and efficiently burnt in the fluidized bed. Complete combustion was obtained similar to the original gaseous fuel, natural gas. The present work revealed that there is a great flexibility in using different forms of fuels in this type of furnaces The results showed thatthe luminosity of sand particle in case of use liquid fuel is higher than that of gases fuel so the heat transfer to furnace wall is high. The luminosity for liquid fuel effect on the average temperature distribution by the range of 60oC lower than that of gases fuel