As a novel technology, coal preheating technology has been proved to be effective on NOx reduction by previous experiments. However, the role of some components of the fuel is still not clear in the preheating process and combustion process. To clarify the effects of volatile and carbon on NOx formation and reduction, three fuels with different volatile contents were used, and the experiments were launched in a bench-scale coal preheating combustion test apparatus. Results showed that the self-preheating burner was widely adaptable to the fuels and the fuels could be stably preheated to be above 860 degrees C. The coal gas mainly containing the combustible components of CO, H-2, and CH4 was generated in the self-preheating burner, accompanying with the high-temperature coal char. Due to the high contents of carbon and volatiles, more combustible components in coal gas could be yielded by the bituminous coal after being preheated. Most of the volatile matters and carbon were released into the coal gas, and the volatile-N was mainly converted into N-2. Because of the reduction of CO and carbon in char, the NOx conversion rates were low enough of the bituminous coal and the semicoke, while the NOx conversion rate of the coal gasification fly ash was a little high for its low carbon content.