By studying the volatile compounds of fermented soy sauces and acid-HVP under the optimized solid-phase microextraction (SPME) and gas chromatography/mass spectrometry (GC/MS) conditions, a novel method of identification of adulteration of soy sauces has been firstly proposed. The optimized SPME conditions were: adsorption time of 30 min, temperature of 50 ℃ and NaCl concentration of 100g/L. Totally, 11 and 15 characteristic compounds were screened in fermented soy sauce and acid-HVP, respectively. By excluding the possible interfering volatile compounds in caramel, 1-octene-3-ol was selected as the index of fermented soy sauces. 1-Phenyl-2-propanone was selected as the indexes of acid-HVP. The new judgment method was proposed and applied for the identification of commercial soy sauces.