Measles encephalitis is a rare disease but it has high mortality rate and severe sequelae and it's pathomecanism is still not clear. Objective of the study was to find out some immunity indexes with fueasles encephalitis in adult. The results showed that, there were difference between case group and control group of CD8, CD45, CD3, HLA-DR and the CD4/CD8 rate. However, there were not difference between case group and control group of CD19, CD4. In conclusion, there were reduction of some immunity cells in measles encephalitis.