Biological toxicity of two kinds of gasoline (90# and 93# ) in soil extracting solution was studied with the help of luminous bacteria. It was high when the concentration of 90# and 93# in the soil extracting solution reached 63.2~90.1 mg/L and 62.7~91.1 mg/L, respectively, and increased with the concentration. EC50 of 90# and 93# in the soil extracting solution was 83.5 mg/L and 83.7 mg/L, respectively. The critical concentration of 90# and 93# in the soil was 2308 mg/kg and 3678 mg/kg, respectively. The results of the study make possible the application of the method of using luminous bacteria to assess biological toxicity of petro-products polluting the soil.