The Er³⁺/Yb³⁺ codoped bismuth germanate glasses containing Ag nanopa rt icles(NPs) were prepared by the conventional melting-quenching method.Physical properties,transmission electron microscope (TEM) images,and luminescence spectr a of the glasses are measured,and the upconversion(UC) mechanism of Er³⁺/Yb ³⁺ codop ed bismuth germanate glass is also discussed.The experimental results show that as the annealing temperature increasing,the precipitation of Ag NPs in glass can enhance the emission efficiency.With the increase of the annealing temper ature,more intense green (527nm,548nm) and red (661nm) UC emission bands ar e observed up to 4.45,5.97and 4.22folds in the glass containing 1wt % AgCl annealed at 420℃ for 24h,respectively.The enhancement of UC emission is attr ibuted to the local field enhancement induced by Ag^0surface plasmon resonance (SPR) and energy transfer from Ag^0to Tm³⁺ ions.