A relatively large negative magnetoresistance has been evidenced in intercalation compounds MnxTiS2(0 <x≤ 0.25) from measurements up to 31 T at 1.8, 4.2, and 77 K. For low Mn concentrationx≤ 0.03, Mn3delectrons are regarded as ‘localized’ spins with thermal fluctuation, while for higher concentrationx> 0.03, a ‘Mn-derived band’ is formed near the Fermi energy. In the layered structure of MnxTiS2, the carrier transport takes place along the host TiS2layers and through the interlayer spaces via intercalated Mn atoms. The observed negative magnetoresistance can be reasonably explained by existing spin fluctuation theories.