Abstract: Objective To observe the effects of papaya on the preventive efficacy of cerebral neurocytes following anoxic damage in vitro.Methods The rat embryonic cerebral neurocytes were cultured with serum-free medium which papaya was added in and were divided into four grous(group Ⅰ anoxic damage 0mg/ml,group Ⅱ anoxic damage 0.1mg/ml,group Ⅲ anoxic damage 0.5mg/ml and group Ⅳ non-anoxic damage 0mg/ml).At the end of the experiment,cultured cerebral neurocytes were collected to detect biochemical indexes and make a pathological observation by using electronic microscope.Results Compared with group Ⅰ,the level of DNA in group Ⅱ,Ⅲ and Ⅳ was increased significantly(P<0.05).The morphological observation showed that the number of neurocytes in group Ⅰ decreased,and the appearance of cell was broken,cell boundary was obscure,synapse were thin and short,and apoptosis bodies can be found.In group Ⅱ and Ⅲ,stretched preparation of majority cells was good,the body of neurocytes was full-grown,cell boundary was integrity,synapses were strong and network was dense,chromatin was partly condense,but apoptosis body can not be found.Conclusion Papaya can prevent the anoxic damage of rat cerebral neurocytes.