Nd3+/Yb3+ co-doped TiO2–La2O3 glasses modified by ZrO2 were fabricated by containerless method. Under the excitation of 980 nm lasers, three intense emissions centered at 521, 545, and 655 nm were observed, which are assigned to the Nd3+: 4G9/2→4I9/2, 4G7/2→4I9/2, and 4G7/2→4I13/2 transitions, respectively. Besides, two very weak emission bands at 496 and 603 nm were also found due to the Nd3+ transition of 2G9/2→4I9/2 and 4G5/2 (or 2G7/2)→4I9/2, respectively. Pumping powder dependence of emission intensity suggests a two-photon adsorption process responsible for the upconversion luminescence. A combined phonon-assisted and cooperative sensitization mechanism is presented to interpret the energy transfer from Yb3+ to Nd3+ ions. In addition, the highest intensity of luminescence was found for the glass with 1.2 mol% Nd3+, and the upconversion efficiency can be enhanced by increasing of ZrO2 content.