4,5-Dimethyl-2-nitrophenol was synthesized via direct nitrification.A maximum yield of 30.3% was achieved at a mass ratio of 3,4-dimethylphenol to nitric acid equating to 1∶1.2.The UV-Vis spectra were compared with those of 3,4-dimethylphenol.The S1→S0 absorption of red shifts relating to 4,5-dimethyl-2-nitrophenol was at about 145 nm.Its crystal structure was also characterized with the nitro-position further verified by analytical data and its real structure was identified.