Aim: Leukemia inhibitory factor (LIF), a pleiotropic cytokine, has been used extensively in the maintenance of mouse embryonic stem cell pluripotency. In this current work, we examined the effect of the LIF signaling pathway in embryonic stem (ES) cell differentiation to a neural fate. Methods: In the presence of LIF (1000 U/mL), the production of neuronal cells derived from embryoid bodies (EB)was tested under various culture conditions. Inhibition of the LIF pathway was examined with specific inhibitors. The effects of cell apoptosis and proliferation on neural differentiation were examined. ES cell differentiation into three-gem layers was compared. Results: Under various culture conditions, neuronal differentiation was increased in the presence of LIF. Blocking the LIF-activated STAT3signaling pathway with specific inhibitors abolished the neuronal differentiation of ES cells, whereas inhibition of the LIF-activated MEK signaling pathway impaired the differentiation of ES cells toward a glial fate. LIF suppressed cell apoptosis and promoted cell proliferation during ES cell differentiation. LIF inhibited the differentiation of ES cells to both mesoderm and extraembryonic endoderm fates, but enhanced the determination of neural progenitors. Conclusion:These results suggest that LIF plays a positive role during the differentiation of ES cells into neuronal cells.