We report the novel near-infrared (NIR) photocatalysis of YF(3) : Yb(3+),Tm(3+)/TiO(2) core/shell nanoparticles. The core/shell nanoparticles show photocatalytic activity under the NIR irradiation. This study demonstrates that the NIR energy can be used as the driving source for photocatalysis besides the UV and visible energy.