Abstract: In this paper, the inhibition activity of Bacillus cereus strain ANTI-8098A at different culture stages against Ralstonia solanacearum, the influence of heat treatment on the inhibition activity and the absorbance values of the culture solution of strain ANTI-8098A at different wave length as well as the correlation analysis between the absorbance values and the inhibition activity were determined. The results showed that inhibition activity began at 12 h culture, getting highest at 48 h. When heated in boiling water bath, the EC₅₀ of strain ANTI-8098A against R. solanacearum increased 14.40%. The absorbance values of the culture solutions at different culture stages at 190, 260, 280 or 400 nm were similar to each other. But during 450-900 nm, the absorbance values of the culture solutions increased with the passage of culture time. The trend of changes in the absorbance values was the same as the trend of changes in the inhibition effect. There was a negative correlation between the inhibition effect and the absorbance values of the culture solutions at 190 nm and positive at 450 nm. The results indicated the antibacterial substances produced by strain ANTI-8098A might not be proteins and could be marked at some wave length from 450 nm to 900 nm, especially at 450 nm.