Objective: To investigate the effect of the injured brain cerebrospinal fluid(CSF) from traumatic brain injury and the hydrocephalus patients on the survival,proliferation and differentiation of neural stem cells(NSCs).Methods: NSCs were isolated and cultured from brain of SD rat.The NSCs were cultured in human bloody CSF from the injured brain patients(the experimental group) or CSF from the hydrocephalus patients(the control group).The growth,proliferation and differentiation pattern of NSCs in two groups were observed at different times.The differentiated cells were identified by immunocytochemistry and their proportions were compared.Results: The NSCs could survive and differentiate both in bloody CSF and hydrocephalus CSF,and part of the cells could grow up by floating in CSF more than ten days.On the second day of the cultivate process,the percentage of NSE positive cells(neurons) in experimental group is significantly higher than that of control group(P<0.05).On the tenth day,the percentage of GFAP positive cells(astrocytes) in the experimental group is significantly higher than that of control group,while the percentage of NSE positive cells in the experimental group is significantly lower than that of control group(P<0.05).Conclusions: The NSCs can survive,proliferate and differentiate both in the bloody CSF and hydrocephalus CSF of injured brain.There was different effect on the differentiation of NSCs between the two groups.