Abstract: The Delphi method is a structured communication technique to obtain subjective evaluation and to forecast on a certain issue based on the consensus among a panel of experts through a series of polling rounds using a questionnaire. Repetitive process, anonymity of the participants, controlled feedback and statistical aggregation are four characteristics that contribute to its extensive application in various areas varying from military, social science to economy, and even to public health in recent years. This paper introduced the concept, process, and crucial characteristics of Delphi method, reviewed its current application to public health, and briefly discussed its prospect for development.