[Objectives]  To clarify the level of insecticide resistance in the diamondback moth (DBM) in Beijing and Hebei and thereby provide information to improve control of this pest. [Methods]  The resistance of the DBM to nine insecticides was evaluated from 2011 to 2015 using the leaf-dipping method. [Results]  Populations of DBM collected from Beijing and Zhangjiakou, Hebei Province, were susceptible to chlorantraniliprole, spinosad, and diafenthiuron. Resistance to Bacillus thuringiensis (Bt), chlorfenapyr and indoxacarb was moderate in some years, but populations were generally susceptible to these pesticides. Resistance to abamectin and chlorfluazuron was consistently moderate, and high resistance to beta-cypermethrin was found. [Conclusion]  Beta-cypermethrin is not suitable for controlling DBM in Beijing and Hebei. The use of abamectin should be discontinued, either permanently or temporarily, to prevent the development of resistance to this pesticide. Other insecticides should be used in rotation, or in alternative ways.