Abstract: A method built on the basis of the toxicity effect of pigments on luminescent bacterium Vibrio fisheri was developed for determining the toxicity and content of pigments. Results showed that there was a positive correlation between inhibitory rate of pigments against luminescent intensity of Vibrio fisheri and pigments concentration in aqueous solution, with a correlation coefficient ranging within 0.8760⁰.9873. EC 50 range was 0.72 ².86mg/L. Inhibitory rate of pigments against luminescent intensity of Vibrio fisheri was also positively correlated with positive concentration in fruit juice, and the correlation coefficient was between 0.9136 and 0.9951. EC 50 range was 1.02².96mg/L. This showed that the toxicity of tartrazine was lower and the toxicity of amaranth was larger. Fruit juice played a role of mitigating the toxicity of the synthetic pigments. The bioluminescence inhibition rate by the pigments in the fruit juice increased with the rate significantly was higher than in aqueous solution. The study provided the initial reference for the acute toxicity testing of the food.