In this paper the combustion experiments on oil shale particles (3-5 mm in diameter) were carried out using a bench scale fluidized bed reactor The characteristics of NOX emission and the effects of several factors in oil shale combustion were investigated. The results indicated that bed temperature, particle diameter and moisture of oil shale have important influences on NOX emission, and while limestone or shale ash added to the bed for SOX capture has no effects. On the Oasis of data concerning NOX concentration vs. time, an unreacted core model was developed, The model predictions agree reasonably well with experimental data.