Up-conversion luminescent materials of Y2O2S: Yb, Tm with different doping concentrations of Tm3+ ion (0.5 mol%–4 mol %) and Yb3+ ion (4 mol%–16 mol %) were prepared by flux method. As Tm3+ doping concentration was 1 mol% and Yb3+ doping concentration was 8 mol%, the blue and red up-conversion luminescent intensity reached the maximum. The concentration quenching of Tm3+ was due to the reducing of the distance between Tm3+ ions and the cross-relaxation increasing. The concentration quenching of Yb3+ was attributed to increasing of nonradiative transition. The blue emission intensity of 1G4→3H6 was always weaker than the red emission intensity of 3F3→3H6, and the blue emission intensity of 1G4→3H6 is similar with the red emission intensity of 1G4→3F4.