Abstract: The activity curves of CAT and SOD in an earthworm can be clearly observed by adopting artificial soil test method, using the herbicide MCPA-Na and Fluroxypyr-1-methylheptylester to pass on a unitary toxicological test to an Eisenia foetida. Results show that under Fluroxypyr-1-methylheptylester stress, with the change of the exposure time, the activity curves of CAT and SOD in an earthworm change roughly in an “S” curve; while under MCPA-Na sodium stress, the two changing activity curves are more like a “U” locus With the same exposure time, the earthworm is found to possess a greater adaptability to MCPA-Nasodium than to Fluroxypyr-1-methylheptylester , which provides us with the basis data for the scientific use of herbicides.