In this paper, we study the influence of Cr3+ on yellowish-green upconversion (UC) emission and the energy transfer (ET) of Er3+/Cr3+/Yb3+ tri-doped in SiO2-ZnO-Na2O-La2O3 (SZNL) zinc silicate glasses under excitation of the 980 nm laser diode (LD). The influence of Cr(3+)on enhancing the red UC emission of Er3+/Cr3+/Yb3+ tri-doped in SiO2-ZnO-Na2O-La2O3 zinc silicate glasses under the excitation of 980nm LD was also investigated. The ET processes between Yb3+, Cr3+, and Er3+, together with the combination of Yb3+-Cr3+-Er3+, which led to the green UC emission intensity of Er3+/Cr3+/Yb3+ tri-doped in SiO2-ZnO-Na2O-La2O3 zinc silicate glasses bands centered at similar to 546 nm have been significantly enhanced. By increasing the concentration of Cr3+ from 0 up to 5 mol.%, we can locate the Commission Internationale de l'eclairage (CIE) 1931 (x; y) chromaticity coordinates for UC emissions of Er3+/Cr3+/Yb3+ tri-doped in the central position of the yellowish-green color region of CIE 1931 chromaticity diagram. Besides, the ET processes between the Yb3+, Cr3+, and Er(3+)are also proposed and discussed.