Liquefied petroleum gas LPG as well as solid fuels like coal and wood ships are used in fluidized bed technology for a wide range of applications. The characteristics of fluidized bed combustion using limestone and sand as bed materials with particles diameter of 0.7 - 1 mm were studied experimentally. An experimental test rig has been designed and manufactured to produce a good fluidization in a wide range of operating conditions. Cold experiments were carried before hot experiments to predict the suitable initial bed height, which has been seen to be 3-cm. LPG fuel, has been used as a gaseous fuel and A/F ratio considered constant during all experiments. The effects of bed material on gas temperature distribution along the combustor height are investigated and presented in the present work. The combustion of coal and wood ships in fluidized bed combustor was verified by adding a continuous flow rates with lesser quantities of LPG.  The photos of the bed in cold and hot states are presented. The heat transfer to the combustor wall was measured from the increase of the cooling water enthalpy and then the combustion efficiency was calculated. The results show the great dependent of the parameters under study on the bed characteristics.