ObjectiveTo study the clinical and laboratory characteristics of handfootmouth disease complicated with encephalitis caused by Enterovirus 71(EV71), so as to improve the quality of diagnosis and treatment .MethodsClinical data of 81 patients with handfootmouth disease complicated with encephalitis were analyzed retrospectively.ResultsOf 81 cases, all had fever, 48 had twitch, 45 startled, and 42 had vomiting. Fiftythree cases were with leukocytosis in peripheral blood； 10 with hyperglycemia, 20 with hypoglycemia ; none with abnormal troponin; 73 with leukocytosis in cerebrospinal fluid. All patients used mannitol to reduce intracranial pressure, 32 used methylprednisolone to inhibit inflammation, and 27 used gamma globulin for support treatment ; except 1 case developed flaccid paralysis of left upper limb,the other cases were clinically cured.ConclusionAll patients with handfootmouth disease complicating with encephalitis caused by EV71 had clinical symptoms of fever and poor spirit, some startled, twitched and vomiting, intracranial pressure should be reduced actively, combination therapy with gamma globulin and glucocorticoid should be chosen appropriately.