Abstract: Objective This study was conducted to analyze the epidemic characteristics of measles and evaluate the serological diagnosis of borderline cases in Changning District of Shanghai. Methods Results of epidemiological survey and serological tests among borderline cases of measles in Changning District from Jan. 2002 to Mar. 2006 were taken into analysis. Results The positive rate of IgM antibody among 156 borderline cases of measles was 85.90%, significantly different among age groups, while the positive rate was higher in yonunger-than-8-month group and over 20-year-old adult group and lower in 8-month-old to 4-year-old group and 5-year-old to 19-year-old group. The positive rate was also significantly different among groups with different immunity history, lower in the immunized group than the non-immunized group and the one with unknown immunity history. The positive rate was different among groups with different serum-collecting time, lowest in the group where serum was collected on the day eruption appeared. Conclusion Conventional immunity of measles vaccine and enhanced immunity should be further conducted to control the incidence of measles among adults. Improving the sensitivity and specificity of immunological surveillance of measles would favor the control and prevention of measles.