The molecular structure of the ground electronic state (X3∑-) of SN- molecular ion has been calculated by using the CCSD(T) method in combination with the correlation-consistent basis sets aug-cc-pVXZ (X=D,T,Q,5). The equilibrium internuclear distance Re , harmonic frequency ωe and dissociation energy De of the molecular ion are derived and are extrapolated to the complete basis set limit. Comparisons of corresponding parameters between this work and those reported previously indicate our results agree well with the experimental data. A reliable potential energy curve is obtained and is perfectly reproduced in the form of the Murrell-Sorbie analytical potential function. we utilized have the potential energy curve to calculate the relevant spectroscopic parameters of the ground state of the system. The vibrational levels and corresponding molecular constants for the X3∑- state are obtained by solving the radial Schrödinger equation of the nuclear motion. Calculations in the present work indicate that an improvement in theoretical computations of SN- molecular ion is achieved.