In this paper, the effects of the two edges, i.e., S and Mo terminals for zigzag MoS2 nanoribbons, on Li atom adsorption and migration were studied from first principles. The lattice constants of NRs are width-dependent. The adsorption energy of single or multi-lithium adatoms is stronger when they are bound to the top of Mo atoms and when a Li atom is closer to the edge of a nanoribbon, particularly the S terminal edge. The symmetric two-sided adsorption configuration is more to form for multi-lithium adatoms. In addition, Li atoms initially adsorbed at the S or Mo terminal edge always prefer to diffuse along their corresponding edges. For other ones, they prefer to diffuse towards their nearby S or Mo terminal edge. These results indicate that zigzag MoS2 nanoribbons can significantly increase the Li binding energy while providing a high mobility path for Li. We hope our theoretical studies will inspire experimental studies on zigzag MoS2 nanoribbons for use as cathode materials.