Trivalent rare earth ions doped materials can convert near infrared photons to different visible emissions and Yb3+ rare earth ions have only two levels of F-2(7/2) and F-2(5/2) in the near infrared region. Yb3+ ions are generally used as sensitizer to obtain high emissions from other rare earths by using similar to 975 nm laser and the near infrared photon energy can be transferred from Yb3+ to other ions. The energy level F-4(3/2) of Nd3+ is little higher than the F-2(5/2) level of Yb3+, so Nd3+ emission may be sensitized by energy transfer from Yb3+ ion. In this work, we studied the luminescence properties of Nd3+/Yb3+ co-doped yttrium silicate (Y2O3: SiO2) nanopowder with a 975 nm diode laser excitation. The emission properties and spectral changes were analyzed at atmospheric pressure and vacuum. The decay and rise patterns were carried out under vacuum (0.01 mbar) and atmospheric pressures.