Abstract: To examine the killing efficacies and it's stability of three pyrethroids indifferent so lvents.Methods: The indoor efficacies of the pyrethroids are determined by direct spraying,the stabilities of those pyrethroids were measured by storing them in different solvents for various times.Results: The best efficacies and the minumum decrease of the KT 50 over the entire storing period for the three pyrethriods are achieved with kerosene as their solvents. Conclusions: To achive a high efficacy and an excellent stability, kerosene is the best solvent for pyrehtroids.Taking the safety,economy efficacy and stability into consideration,the water,if supplied with proper emusifier and stabilizer,in the best solvent of the household insecticides in the future.