Enhancement effect of earthworm (Pheretima sp.) inoculation on the remediation efficiency of soil phenanthrene (Phe) and pyrene (Pye) pollution by Pogonatherum paniceum was studied by pot experiments in a green house. Results showed that earthworm activity promoted the growth of Pogonatherum paniceum in soils with initial concentrations of Phe and Pye ranging from 20.05 to 322.06 mg•kg-1, and apparently increased the biomass ratios of root to shoot of the grass. After a 70-day earthworm inoculation, averagely 76.7% of Phe and 70.6% of Pye were removed from the soils planted grass, which were 8.31% and 9.45% higher than those without earthworm inoculation, respectively. Earthworm activity showed higher enhancement effect for the remediation of Pye than for Phe at the same pollution level. Among all possible pathways, the plant-microbial interaction was proved to be the primary means of PAHs degradation, either with or without earthworm activity, and its contribution to the removal of Phe and Pyr in planted soils accounted for up to 46.59% and 42.78% of the total removal, which were 5.03% and 6.14% higher than those in corresponding soils without earthworm (with 41.56% degradation for Phe and 36.64% for Pyr). Results suggested a feasible way for the establishment of high efficiency phytoremediation of soil PAHs pollution by inoculating earthworms, especially for those PAHs with more benzene rings in their molecular structures.