The Ho3+/Yb3+codoped TiO2 sol was prepared through SolGel method, Ti(OC4H9)4 was chosen as a precursor, and ethanol as impregnant, acid as catalyzer, and its upxonverted luminescence mechanism was studyed. By means of Xray diffraction, energy spectrum and scanning electron microscope samples characterization, and the results show that the structure of the sample is rutile, samples contained by powder doped Yb, sample Ho and element of very small particles diameter is about 100 nanometers, spherical shape, and has obvious reunion phenomenon. At room temperature for 980 nm wavelength selection center, maximum output power for the diode laser 500 mV do stimulate light stimulates samples. In TiO2∶Ho3+ / Yb3+ sample find red and green, the emission strength of red is two times of green. When the doping concentration of Yb3+ is 2.5 mol%, fluorescence spectroscopy 543 nm conversion in observed strong green emission.The mechanisms of the upconversion luminescence were researched.