摘要LY-04 and WSQIF are newly-synthesized compounds which were presented by the Institute of Pesticides Chemistry, Central China Normal University. LY-04 belongs to α-oxophosphonic acid derivatives, while WSQIF is an aromatic acetyl oxophospho04 and WSQIF were determined in S. obliquus cells at 24h, 48h, 72h, 96h represented by cell density. Our data showed that the 24h, 48h, 72h, 96h EC50 of LY-04 were 1983mg/L, 2943mg/L, 240mg/L and 65.0mg/L acetone, respectively, and the 24h,48h, 72h, 96h EC50 of WSQIF were 15.9mg/L, 53.0mg/L, 98.0mg/L and 28.8mg/L respectively. LY-04 displayed a higher insecticidal activity, while WSQIF showed a higher phytocidal activity. As LY-04 and WSQIF were designed to act as insecticide and herbicide, respectively, the results were in contrast to the anticipated ones. According to the toxicant classification standard,EC50 of both substances was far higher than 3mg/L, while the toxicity of LY-04 and WSQIF to aquatic algae were fairly low, indicating that these two pesticides are rather safe to the aquatic ecosystem.