The burn-out characteristics of oil shale semi-coke, corn stalk and their blends were invest-tigated by thermogravimetric analysis, the maximum burning rate, temperature of the maximum burning rate and burnout index were investigated. Batch charges of samples were burnt in a laboratory scale fluidized bed. The effect of particle size, initial bed temperature, air flow rate and different semi-coke percentages on the burnout time was investigated. The results have shown that an increase in bed temperature or air flow rate was associated with a decrease in burnout time. On the contrary, an increase in particle mean size led to an increase in burnout time. The most significant difference occurred with mixtures on the burnout time. The trend is increasing and then decreasing