This experiment studied bioactivity and control effect of the 25%JS7119 EC for different developmental insect stages of Panonychus citri(McGregor). The results of bioactivity assay showed that active compounds 25%JS7119 EC for Panonychus citri adults of the slide dipmethod, the median lethal dose (LC50) was 115.921 7 mg/kg. It was higher than the LC50 of the reference pesticides 5% fenpyroximate SC and 15% ridaben EC. The results of bioactivity assay showed that active compounds 25%JS7119 EC for Panonychus citri adults of the leaves-tip bioassays, the LC50 was 0.639 4 mg/kg . It was higher than the LC50 of the reference pesticides 15% ridaben EC. It was lower than the LC50 of the reference pesticides 5% fenpyroximate SC. The results of bioactivity assay showed that active compounds 25%JS7119 EC for Panonychus citri nymphs and egges apply the leaves-tip bioassays, the LC50 respectively was 4.478 3 mg/kg and 644.391 73 mg/kg. The LC50 of they both were higher than the reference pesticides 5% fenpyroximate SC and 15% ridaben EC. But the control effect of 25%JS7119 EC in field showed 25%JS7119 EC 625 times was better and more lasting to Panonychus citri the control effect of 25% JS7119 EC 625 times was equivalent to 15% ridaben EC 1 500 times, the practical results showed that 25% JS7119 EC have better control effect in field. It can be promoted the use of a large number of production in field.