PP, an EPDM prior to crosslinking, and PE particles are fed into a twin screw extruder and melt-kneaded so that the EPDM is dynamically crosslinked, whereby a sliding material for weather strips formed of an olefin-based TPV in which the PE particles are dispersed is produced. The amount of the PE particles blended is 10 parts by mass to 90 parts by mass with respect to 100 parts by mass of the total amount of the PP and the EPDM. It is preferable that the PE particles have an average particle diameter of 30 μm to 200 μm before the feeding, and are micronized by the melt kneading to have an average particle diameter of 10 μm to 50 μm in the produced sliding material for weather strips.