Provided are a binder resin composition for toner excellent in low-temperature fusing property, storage stability and durability, a toner for developing electrostatic images that contains the binder resin composition for toner, and a method for producing the binder resin composition for toner. The binder resin composition for toner contains a resin composition (C-P) prepared by condensing an acid group-having crystalline resin (C) and a polyalkyleneimine, and an amorphous resin (A).