To provide a bristle material for toothbrushes and a toothbrush having appropriate flexibility and high durability and having an excellent cleaning effect such as plaque removal.

This bristle material for the toothbrush formed of cut bristles of monofilaments formed of thermoplastic resin composition of 90-60 wt.% of polyamide resin and 10-40 wt.% of polyester resin, has a plurality of fine slots extending in the fiber axis direction on the whole surface of the cut bristle.