An object of the present disclosure is to provide a method for producing a NOx storage-reduction catalyst capable of inhibiting decreases in NOx purification performance following exposure to high temperatures. The present disclosure achieves the aforementioned object with a method for producing a NOx storage-reduction catalyst, comprising: (A) supporting potassium compound particles on catalyst support particles by using an potassium dispersed water containing the potassium compound particles, and (B) calcining the catalyst support particles supporting the potassium compound particles; wherein, the potassium compound particles are at least one type selected from the group consisting of oteracil potassium, potassium tetranitroacridone, potassium tetraphenylborate, and potassium tetranitrophenothiazine-9-oxide.