An electrical heated test rig with nonintrusive multipoint sampling analysis system was built up. On such a test rig, the experiments of time evolution of methane reburning and combustion process have been carried out. In the methane rebuming process, the concentrations of O-2, CH4, C2H4, C2H6, and NO decrease during 0.2-1.0 s, while the concentrations of C2H2, CO, H-2, and HCN increase within the same time. Through comparison of the time evolutions of methane reburning and combustion process, the changing trends of CH4, C2H2, C2H4, C2H6, H-2, O-2, and CO are similar, and the concentrations of CH4, C2H4, and C2H6 in the methane rebuming process are slightly higher than these in the methane combustion process, while the concentration of C2H2 in the methane rebuming process is obviously lower than that in the methane combustion process. The experimental results suggest that C2H2 is the key hydrocarbon in the methane rebumin process, and the NO reduction by methane as the rebuming fuel mainly proceeds via the reacton with C2H2. The further validating experimental results show that C2H2 is of the most significant effects on NO reduction when compared with CH4, C2H4, and C2H6 at the same stoichiometric ratio. In the case with C2H2, the NO reduction efficiency is aboue 90%. But for CH4, C2H4, and C2H6, the NO reduction efficiency is only about 28, 35, and 45%, respectively.