Abstract: The acute toxic effects of No.0 diesel oil wateraccomodated fractions(WAFs) and dispersed oil (disWAFs) on sea urchin were studied, and the response of antioxidase(superoxide dismutase, SOD; catalase, CAT; glutathione Stransferase,GST) in digestive gland to disWAFs were tested. Hemicentrotus pulcherrimus was exposed to different concentrations of disWAFs (0.5,1,2 mg/L) for 13 days, and then transferred into clean sea water for 11d restoring experiment. The results showed that the disWAFs was more toxic, with 24, 48, 72, 96h LC50 values of 11.7,9.1,7.4 and 5.1 mg/L respectively. The activity of antioxidase was statistically significant doserelated effect in different disWAFs concentrations. Under the same doseconcentration exposure, SOD, CAT and GST activities increased first and then decreased with the prolonged exposure time. This trend was most significant in GST activity. The activities of SOD, CAT and GST of all concentration groups recovered to the corresponding control level after recovery experiment. According to the data, SOD, CAT and GST can be taken as biomarkers to monitor benthic marine oil pollution and provide.

Key words: No.0 diesel oil wateraccomodated fractions (WAFs), No.0 diesel oil emulsion (disWAFs), antioxidase, Hemicentrotus pulcherrimus, No.0 diesel oil wateraccomodated fractions (WAFs), No.0 diesel oil emulsion (disWAFs), antioxidase