Twenty eight aryl pyrazole derivatives containing 5-fluorouracil were designed and synthesised via the key intermediate 1-aryl-3-methyl-1 H-pyrazole-5-carboxylic acid. The structures of target compounds were confirmed by 1H NMR, FT-IR, EA and their insecticidal activities were evaluated. The bioassays revealed that aryl pyrazole derivatives containing 5-fluorouracil exhibited excellent insecticidal activities against Culex pipiens and Musca domestica at a concentration of 0.1%. Some compounds still showed good insecticidal activities even at a concentration of 0.05%.