Abstract: Microbe species and amount,and nutrient sorts and concentration all have effects on treatment efficiency in the microbe treatment of oily soil.Adding effcient crude-oil degrading bacteria and optimum nutrient to oily soil at the same time is the most efficient treating mode.The optimum adding amount of bacteria is 6mL/kg or more,and the optimum adding of nutrient is made in case of C∶N=40∶1.