Abstract: To explore impacts of a new pesticide adjuvant LD-10 (Patent license number: 200810103519.7) and two commonly used pesticide adjuvants NP-10 and NP-4 on non-target organisms in soil, acute toxicities of LD-10, NP-10 and NP-4 to earthworm (Eisenia fetida) in natural soil and sterilized soil were determined. Results show that in the natural soil, the 7d w(LC₅₀) of LD-10, NP-10 and NP-4 for earthworm was 482.58, 1077.50 and 343.17mg•kg ^-1, respectively, and 14d w(LC₅₀) 438.38, 984.64 and 316.65 mg•kg^-1, respectively, and in the sterilized soil, the 7d w(LC₅₀) of LD-10, NP-10 and NP-4 for earthworm was 350.71, 960.95 and 309.63mg•kg ^-1, respectively, and 14d w(LC₅₀) 320.24 , 745.99 and 274.76 mg•kg^-1, respectively, which shows that in both the natural and sterilized soils, the three agents are all low in toxicity to the earthworm, and follow the order of NP-10 < LD-10 < NP-4 in toxicity, however, they are more toxic in the sterilized soil than in the natural soil.