Abstract: AIMTo study the sodium nitrite induced DNA mutation by convolution spectrometry (CS). METHODSThe spectra of sodium nitrite-induced mutative calf thymus DNA was compared with ego criteria based on Spectra of the primary DNA within the wavelength range from 200 to 340 nm. Distilled water served as blank and normal saline served as negative control. Any difference was quantitatively expressed by differential value (δ) of convolution spectra. Near-infrared spectroscopy was employed as the reference method. RESULTSThe differential value was positively correlated with the increasing time and concentration of sodium nitrite. δ values increased to 1.37%, 2.41% and 5.44% respectively within 2-hour's reaction between calf thymus DNA and 0.5, 0.05 and 0.005 μg·mL^-1 sodium nitrite, while on the contrary, changes could be hardly observed on the corresponding UV absorption spectra. The results were also confirmed by their corresponding near-infrared spectra. CONCLUSIONThe δ values can be used to represent the compound's strength of mutagenesis. Every convolution procedure takes less than one minute, so CS provides a fast, simple and inexpensive alternative method to determine chemical or medicinal DNA mutation.