Through the method of simulating the heavy metal pollution in farmland, the graphite oven (GF-990) atomic absorption was used for analyzing the regulations of the earthworms inducing the soil Cd2+ absorbed by the perennial ryegrass.The result indicated: (1) under the circumstance of the soil Cd2+ density of 3~6 mg·kg-1, the positive relevance appeared extremely remarkably that the contents of Cd2+ in underground portions of the perennial ryegrass relate to the earthworm quantity (r=0.883 2~0.986 2), but in the portion above ground the positive relevance did not appear extremely remarkably (r=0.345 5～0.325 4); And the negative relevance appeared remarkably that the contents of Cd2+ in the soil relate to the earthworm quantity (r=-0.588 7～-0.678 4).(2) Under the conditions of isometric number of earthworms, the more the density of Cd2+ in the soil, the more the increase of Cd2+ in both portions under and above ground of perennial ryegrass.(3) Under the same soil environment, the negative relevance appeared that the number of earthworms relates to the contents of Cd2+ in the earthworms (r=-0.982 0～-0.991 6).