Abstract: In order to explore the repair effect of arachidonic acid(AA)on ultraviolet radiation(UVR)damage of organism,a UVR injury model of Caenorhabditis elegans was established. The effects of AA on the life span,exercise capacity,spawning ability and reactive oxygen species(ROS)levels of Caenorhabditis elegans following UVR were investigated. Results showed that after treatment with AA,the 7 MJ/cm² dose UVR-damaged Caenorhabditis elegans could increase the life span,movement and oviposition ability of the Caenorhabditis elegans. The effect was significant when the AA concentration was 50 μmol/L. The exercise and oviposition ability were increased by 63.6% and 96.6% respectively compared with that from the control group,and the ROS level in vivo was significantly decreased at this concentration(p<0.05). Inconclusion,AA has certain repair effect on Caenorhabditis elegans after UVR.The results provide a theoretical basis for the AA UVR in the functional food or medicine research and development.