The remediation of diesel fuel contaminated soil over a 2-year period by the plant-microorganism synergy was evaluated. Results indicated that the growth of Astragalus adsurgens was affected significantly, when the diesel fuel concentration was higher than 10 g kg(-1) dry soil. After a 2-year period, the removal of diesel fuel was >67%, and about 58-70% removal of aromatic hydrocarbons was obtained in these treatments. The removal of diesel fuel and its components was 13-30% higher than that of plant alone. These results show that an appropriate plant-microorganism synergy may serve as a low-cost, effective remedial technology for diesel-contaminated soil.