Resonance-enhanced multiphoton ionization (REMPI) spectra of N32S and N34S have been recorded in the range of 35700―40200 cm-1. The radical was generated by a pulsed dc discharge of a mixture of SF6 and N2 under a supersonic free jet condition. All the 16 observed bands of N32S radicals have been assigned, among which 12 bands belong to three transition progressions (v′=0-4, 0), (v′=1-4, 1) and (v′=2-4, 2) from the X2Π ground state to the B′2∑+ upper state and the rest correspond to (9, 0), (10, 0), (11, 0) and (12, 0) bands of B2∑-X2Π transition, respectively. Analysis of the rotationally resolved spectra yields exhaustive spectroscopic constants of both the X2Π ground state and the B′2∑+ excited state. The electronic transition bands of the isotopic molecule N34S have been rotationally analyzed for the first time and the rotational constants of the ground and upper states have been determined simultaneously.