Both hydrocarbon-contaminated yellow loessial soil from Shanbei Changqing oil field and tall fescue were chosen for biodegradation testing. Three groups of bacterial floras, TJQ, JQ1 and JQ2, were obtained from the chosen soil, hydrocarbon-polluted slurry, and crude-oil-polluted garden soil after 90d domestication respectively. These bacterial floras were mainly composed of bacteria and fungi. The biodegradation results showed that the inoculation of bacterial floras JQ1, JQ2, TJQ and their various combinations could accelerate the oil-biodegrading process, the oil removing rate within 30d incresed by 13.8%-25.4% compared with the control group, there into, JQ1 and JQ2 was the best combination. With tall fescue planting in above inoculated soils, the oil-biodegrading rate accelerated during the germination and seedling periods, the highest oil removing rate within 30d reached to 49.8%, 15% higher than that of non-planting control groups. The best combination was JQ1+ JQ2+tall fescue, the amount of microbes increased 1-2 orders of the magnitude, and the microbial fluorescein diacetate (FDA) activity increased by 0.53-1.26 times. The rhizosphere regulation of tall fescue reinforced the oil-biodegrading process obviously.