Epidemic meningitis is a viral meningitis. The cerebrospinal fluid characteristics of epidemic meningitis are as follows: i. When the cerebrospinal fluid of epidemic meningitis is tested, there is no abnormal performance in cytological diagnosis. Second, the biochemical examination of the cerebrospinal fluid of epidemic meningitis, and there are no major changes, there may sometimes be a mild increase in chloride, but it is not obvious. Third, routine examination of the cerebrospinal fluid in epidemic meningitis will reveal a mildly elevated cell content, with a few dozen cells per milliliter and no more than a hundred. These features of the cerebrospinal fluid in epidemic meningitis can be clearly distinguished from tuberculous meningitis and bacterial septic meningitis, which are of great importance in the clinical diagnosis process.