An experimental study on NO reduction by biomass gasification tar had been carried Out on the now reaction system. Tar is so complex that tar model compounds were selected to reduce NO. Those model compounds were benzene, toluene, styrene, and phenol, According to the thermogravimetry-mass spectrometry (TG-MS) analyses of pyrolysis and gasification of rice straw, corn Stalk, and corncob, these four compounds are main compositions of biogas tar. Experimental results show that the four model compounds have different effects on NO reduction, and We Study their NO reduction effect individually in this paper to shed light on the reburning effect of the main species of tar. NO reduction efficiency, eta, is obtained from fuel-lean to fuel-rich conditions of each fuel in the temperature range of 900-1400 degrees C. In general, phenol leads to a better performance under the experiment conditions, and NO reduction efficiency is maintained at almost 30-40% and changes little with temperature. For benzene, NO reduction efficiency is correspondingly low under the temperature ranges. Toluene and styrene, which have a hydrocarbon substituent attached to the benzene ring, perform better than benzene. The NO reduction efficiency of toluene is low at lower temperatures but increases a lot with increasing temperature, and the fuel-rich condition is helpful for reducing NO. NO reduction efficiency of styrene increases a little with temperature and changes a lot with the bulk equivalence ratio under higher temperatures (1100-1400 degrees C). but the maximum efficiency occurred at almost the same bulk equivalence ratio, phi = 1.27. For benzene and phenol, fuel-lean conditions favor their performance. The results will instruct further research and engineering application of biogas reburning.