Despite numerous experimental studies of the NOx emission of coke combustion, there is no good computational model for NOx emission of the coke combustion. In this study, experimental studies of exhaust emissions of coke combustion were conducted by using micro-sinter equipment. Unreacted-core model was applied to kinetic analysis. The calculated NOx content curve described the measured data well, and the peak and integral total NOx difference values between the calculated and experimental data were 2.7 ppm and 0.15 mL, respectively, which illustrated successful application of unreacted-coremodel for the NOx emission of coke combustion. The equation also illustrated that particle size of coke breeze and O-2 concentration had a great influence on the NOx emission of coke combustion.