Abstract: A sparse nested array concept of distributing the right-side elements of two level augmented nested array (ANA) sparsely was proposed for degree of freedom (DOF) enhancement. The new strategy was arranged to make the distances between the right-side elements and the right most sensor in the middle subarray of ANA larger than <i<N</i<<sub<1</sub< to extend the furthest aperture successfully. In order to keep the continuity of virtual aperture, a new nested array, referred to as one side sparse nested array (OS-SNA), was proposed. Compared with the improved nested array ANAI-2 and maximum inter-element spacing constraint (MISC), the new nested array can generate more consecutive lags. Simulation results show the superiorities of the proposed OS-SNA in DOF and the precision estimation.