Objective : To investigate the effects of Jagged1 protein on the differentiation of neural stem cells. Methods : Neural stem cells were isolated from mouse embryonic brain and cultured in vitro. After the neural stem cells were identified , Jagged1 protein was used to induce the differentiation of the neural progenitor cells and the number of differentiated neurons was counted. Results : The cultured cells could proliferate and differentiate into neurons , astrocytes and oligodendrocytes. After Jagged1 protein treatment the number of neurons in differentiated cells decreased compared with that in control group , which could be counteracted by gamma-secretase inhibitor. Conclusion : Neural stem cells are self-renewal , multipotent and can express Notch receptor. Jagged1 protein can inhibit neural stem cells differentiation into neuron through Notch signaling pathway.