As promising candidates for organic molecule-based ferromagnets, we have investigated several stable thioaminyl radicals in the solid states. In addition to N-[(2,4-dichlorophenyl)thio]-2,4, 6-tris(3-chlorophenyl)-phenylaminyl (1) which we have already reported (Mel. Cryst. Liq. Cryst., in press (1995)), other thioaminyl radical crystal showing ferromagnetic behaviors have been found. Thus, N-[(2,4-dichloro-phenyl)thio]-2,4, 6-tris(4-chlorophenyl)phenylaminyl (2) radical shows one-dimensional ferromagnetic behavior. The magnetic behavior has been well interpreted in terms of the one-dimensional Heisenberg model with ferromagnetic intermolecular interactions of J/k = 14.0 K. In contrast, N-[(2,4-dichlorophenyl) thio]-2,4,6-tris(4-chlorophenyl)-phenylaminyl (3) shows antiferromagnetic behavior described by an alternating linear chain model with J/k = -8.4 K and alpha = 0.55.