The vortex state in a single crystal of the layered organic superconductor κ-(BEDT-TTF 2 Cu(NCS) 2 , where BEDT-TTF (or ET) is bis(ethylenedithio)tetrathiafulvalene, was studied by 1 H-NMR. Under a low field region around 0.75 T, the vortex glass-liquid transition was demonstrated by a diverging of the longitudinal nuclear spin relaxation rate and peak-broadening in spectra. Under a high field region near the upper critical field H c2 (0) ≃7 T, the curvature of nuclear spin relaxation curves showed a drastic change at the temperature where the emergence of the quantum vortex slush state was reported. The mechanism in this curvature change was discussed in terms of the fluctuating field produced by fragments of vortex glass.