Under the infinitesimal transformations of Lie group, Noether-Lie symmetry of Nielsen equations for a singular variable mass nonholonomic system with unilateral constraints is studied. Differential equations of motion for Nielsen equations of the system are established. The definition, criteria and propositions for Nielsen equations of the system are given. Noether conserved quantity as well as generalized Hojman quantity is obtained. An example is given to illustrate the application of the results.