Photodynamic therapy based on Lanthanide-doped Upconversion nanoparticles (UCNPs)has generated a large amount of interest due to the high penetration depth of 980 nm near-infrared light.However,the 980 nm laser will cause harsh overheating effects due to the water in biological tissues has huge absorption around 980 nm.In this work,we shift the excitation light to 808 nm through fabricated NaYF4:Yb/Ho@NaYF4:Nd core-shell UCNPs to minimize overheating effect.A photosensitizer,Rose-Bengal(RB),was covalent with UCNPs because RB molecules can efficiently absorb the 540 nm emission of UCNPs,this construct denoted as RB-UCNPs.The high 1O2 of RB-UCNPs was detected from 1,3-diphenylisobenzofuran consumption.In vitro and in vivo tests also demonstrated that this RB-UCNPs construct can efficiently kill cancer cells.The viability of Hela cells was 30%after irradiation 808 nm light for 10 minute(0.67W/cm2).In vivo PDT showed tumor inhibition ration about 60%compared with 980 nm laser excited.Moreover,the 650 nm emission of UCNPs was used for bioimaging.These results indicate that the RB-UCNPs construct is a promising agent for imaging-guide PDT with low overheating effect.