Abstract: Objective: To investigate the changes of platalet parameters and its clinical significance in neonates with hypoxic-ischemic encephalopathy(HIE).Methods: Forty-six neonates with HIE were included in the study.Their blood platelets count(BPC),mean platelet volume(MPV) and platelet distribution width(PDW) were detected at the acute stage(under three days after birth) and the recovery stage(seven days after birth).The data were compared with those from 35 healthy controls born whthin 3 days.The 46 cases of HIE were then divided into three growps according to the severity of their disease,and the data from these three groups were compared.Results: At the actue stage,BPC in the neonates with HIE was obviously lower than that in the control group,and MPV and PDW were obviously higher.There was remarkable difference(P<0.001).At the recovery stage,BPC in HIE group increased obviously to the level of control group(P<0.001),and MPV and PDW descended to the level of control group(P<0.001).BPC in the HIE group reduced along with the aggravation of the condition gradually,while MPV and PDW increased.Conclusions: The change of platecet parameter is of great value in judging HIE and its severity.