β-NaYF4∶Er3+ upconversion nanoparticles were prepared by using coprecipitation method. The Ag nanocubes prepared by chemical reduction method and the Au nanorods prepared by seed-mediated growth method were doped into β-NaYF4∶2%Er3+ nanoparticles to form nano-composites, respectively. Therefore the enhancements of upconversion luminescence on β-NaYF4∶Er3+ NPs were achieved through surface plasmon resonance. The enhancement was up to 4.0 times with 60 μL Ag nanocubes doped, while the enhancement was up to 7.8 times with 60 μL Au nanorods doped. Codoping Ag nanocubes and Au nanorods into β-NaYF4∶2%Er3+ nanoparticles, great enhancement of upconversion luminescence reaching 16.0 times was obtained via co-enhancement of excitation and emission.