Objective To investigate the variation characteristics of peripheral platelet parameters in children with dengue fever and to assess their use and value in diagnosis,prognosis and treatment for dengue fever.Methods Platelet parameters of 69 pediatric patients with dengue fever in acute febrile phase and remission period and 103 healthy controls were compared.The difference of platelet parameters between the liver function injury group and the normal liver function group,the coagulation dysfunction group and the coagulation function normal group,the severe group and the mild group with dengue fever was compared,the causes of thrombocytopenia in children with dengue was investigated so as to better understand the situation of bone marrow producing platelets.Results P-LCR,PDW,MPV were significantly higher in patients in acute febrile phase of dengue fever,compared with the healthy subjects(P＜0.01),while PCT,PLT were significantly lower in patients in acute febrile phase of dengue fever,compared with the healthy subjects(P＜0.01).MPV was significantly lower in patients with abnormal hepatic function when compared with patients with normal hepatic function(P＜0.05),while other platelet parameters did not show significant differences(P＞0.05).PLT and PCT were significantly lower in the severe patients than those in the mild patients(P＜0.05),while other platelet parameters did not show significant differences(P＞0.05).Peripheral platelet parameters did not show significant differences between patients with or without abnormal coagulation function (P＞0.05).Conclusion Peripheral platelet parameters may play a role in the diagnosis,treatment and prognosis of dengue fever in children.