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YVO_4:Er~(3+), Yb~(3+) with varying Yb3+ concentrations were prepared by a precipitation method. The results of X-ray difffaction (XRD) show that all the samples have a tetragonal zircon structure; the calculated average crystallite sizes are in the range of 14-22 nm. The lattice constants and cell volume of the samples decrease slightly with the increase in Yb~(3+) concentration. The upconversion luminescence spectra of all the samples were studied under 980 nm laser excitation. The strong green emission is observed, which is attributed to the 2~H_(11/2 )→4~I_(15/2) and 4~S_(3/2)→4~I_(15/2) transitions of Er~(3+), and the red emission peaks in 650-675 nm can be ignored. The emission intensity for the sample depends on the Yb~(3+) concentration. These results reveal that the upconversion processes of YVO_4:Er~(3+), Yb~(3+) are related to the structure and the doping Yb~(3+)concentration of the sample.