The phenanthrene and pyrene contaminated soil was degradaded by immobilized-imbedding the selected Zoogloea sp. The degradation rate was determined under various amounts of inoculation and concentration, and the result showed that there was the best degradation rate at 5%. After 168 h, the degradation rate of immobilized Zoogloea sp. to phenanthrene and pyrene was 84.89% and 76.94% respectively. While, the degradation rate of the native bacterium was only 27.85% and 19.65% at the same condition. So the Zoogloea sp. had the better degradation ability. And, Zoogloea sp. distributing shape in immobilized carrier was studied with electric scan-photo, it inferred that immobilized bacterium had the better degradation rate.