Abstract: Selenium(Ⅳ) and iron(Ⅲ) can catalyze the oxidation of dimethyl yellow discoloration reaction by hydrogen peroxide under acidic conditions. It also found that the catalytic effects of the two ions have no additive properties. Based on this research, the advantages of artificial neural network were adopted to handle the experimental data and a new catalytic kinetic spectrophotometric method for the simultaneous determination of selenium(Ⅳ) and iron(Ⅲ) with artificial neural network was established. The best reaction conditions were discussed and the structure of the neural networks was optimized. The recovery were between 95%~105% of the determination in synthetic samples and the results showed that the method is sensitive, accurate and suitable for the determination of selenium and iron in tobacco samples.