Sodium benzoate in soy sauce was detected using surface-enhanced Raman spectroscopy ( SERS )and silver sol as the reinforcement substrate.In the first step,silver sols prepared with different concentrationsof sodium citrate were used to test the elfeet of their dose on SERS signal; In the second step, the Ramancharacteristic peaks of sodium benzoate at 848 cm~' ,1 012 em"' and 1 603 em"' were determined by comparingthe SERS spectra of the sodium benzoate standard and its solution and sample solution.In the last step, theSERS speetra of sodium benzoate samples in 12 different mass concentrations of soy sauce were collected ,andthe model established by univariate linear regression was analyzed.The results showed that SERS technologyusing silver colloidal as the substrate could be used for rapid quantitative detection of sodium benzoate eontent1n Soy SauCe.