The angular dependence of the H-NMR 1 -NMR lineshape in the magnetic ordered state of (TMTTF) 2 SCN was precisely analyzed. The most possible SDW wave-number was found to be commensurate, (, , 0), and the amplitude, 0.14 μ B /molecule. These SDW parameters are identical with those of (TMTSF) 2 Br determined previously in spite of large difference in transport properties.