Abstract: Objective To the provide the evidence for early diagnosis and treatment of viral encephalitis by analyzing the features of cerebrospinal fluid (CSF) from viral encephalitis patients. Methods The clinical data about and routine, biochemical and cytological fndings in CSF from 124 viral encephalitis patients admitted to our hospital from January 2004 to December 2012 were retrospectively analyzed. Results Of 124 patients, 105 (84.6%) were found to have abnormal CSF, including elevated intracranial pressure in 46 (37.1%), increased white cell counts in 94 (75.8%) with a peak of 360×10⁶/L. Of 124 patients, 103 (83.1%) were found to have abnormal CSF cytology characterized by lymphocyte pleocytosis (86.4%) or monocyte pleocytosis (9.7%), 70 (56.5%) had an increased protein level and 6 (4.8%) had a decreased glucose level. However, their chloride level was normal. The CSF was normal in 19 patients (15.4%). Conclusion Routine, biochemical and cytological examination of CSF play an important role in early diagnosis of viral encephalitis.