To provide a method for producing a resin composition with good nano dispersion.

A method for producing a resin composition by melt-kneading a first polymer and a second polymer having a higher softening point than the first polymer comprises a first melt-kneading step (A) in which the polymers are kneaded at the first temperature higher than the softening point of the second polymer, and a second melt-kneading step (B) in which the polymers are kneaded at the second temperature lower than the first temperature, and by shear stress higher than that of the first melt-kneading step.