Since the first report in Canada in 1957, there have been outbreaks of HFMD in different parts of the world and in China at different times, and some surveys have shown that HFMD is prevalent in the population once every 2-3 years. The onset of the disease is mainly in spring and summer, spread through saliva, droplets, feces through the gastrointestinal tract, respiratory tract and close contact, the susceptible population is preschool children, no specific treatment, mainly symptomatic treatment, self-limiting disease, most of the prognosis is good, a few complications of brain, lung and heart dysfunction leading to death. Hand, foot and mouth disease is an infectious disease mainly caused by oral mucosa and hand, foot and skin lesions of enterovirus (RNA virus) Coxsackie (COX) A16 and A5, A10, A9, B5, B2, echovirus, EV71 (type A, B, C) virus, etc. Coxsackie virus can cause myocardial damage and neurological disease, while EV71 has neurophilic characteristics, which is difficult to distinguish from clinical manifestations. It is difficult to differentiate them from each other. Currently available pathogenic tests: (1) Nucleic acid detection: PCR, RT-PCR and microchip technologies for blood, throat swabs, stool, cerebrospinal fluid and herpes of infected children can detect enterovirus nucleic acid, specific EV71 nucleic acid and COXA16 nucleic acid. (2) Viral culture: isolation of viral particles is the most objective basis for determining the diagnosis. (3) Serologic examination: A neutralization test is performed by taking double sera from patients in the early and recovery periods, and if there is a 4-fold or higher increase in specific antibodies, it is diagnostic. Using ELIsA method to detect specific IgM antibody also has diagnostic significance. From the analysis of our survey, EV71 and COXA16 infections accounted for 38.2% of all cases in Kunming in 2010, EV71 infection accounted for only 12.42% of all cases, while COXA16 accounted for 25.7% of all cases. The majority of severe cases are due to EV71 infection. EV7l is a highly neurotropic virus, and the brainstem is the most vulnerable site for EV71 infection. It is generally believed that EV71 directly invades the nervous system causing continuous excitation of the adrenal medulla, which on the one hand mediates pulmonary vasoconstriction and causes an increase in cerebrovascular fluid venous pressure; on the other hand, it causes intracellular calcium aggregation and damage to membranous structures, and increases capillary permeability, resulting in acute pulmonary edema, which can be seen on x-ray chest examination as increased texture in both lungs, network-like, dotted, or large shadows, unilateral predominantly in some cases, and rapidly Some cases are unilateral, and rapidly progress to bilateral large shadows. Magnetic resonance or CT examinations show predominantly brainstem damage, with foci in the upper brain and basal ganglia, and in some cases involving the spinal cord and dura mater. It is difficult to make a clinical diagnosis without showing the typical cross syndrome of cranial nerves, pyramidal tracts and sensory conduction tracts, because pediatric brainstem encephalitis is rare and is a metamorphic reaction to pathogenic infection in the brainstem. It is necessary to strengthen the prevention and control of HFMD in Kunming, especially in April, May, June and July, and to enhance the publicity of HFMD knowledge, strengthen the morning inspection and related isolation and disinfection system in kindergartens and schools, and raise the awareness of medical personnel about the epidemiological characteristics of HFMD, especially about the danger of severe cases of EV71 infection, which will play a key role in the prevention and control of HFMD.