Echo questions are prevalent in verbal conversations,rather than a marginalized phenomenon.Researchers have increasingly realized the importance of echo questions in both daily communication and institutional interaction.However,previous studies on echo questions are not sufficient and systemic,rarely focusing on the characteristics of echo questions in outpatient departments in the hospitals.Based on the naturally occurring conversations between doctors and patients in outpatient departments,this study investigates the echo questions in doctor-patient conversation in some outpatient departments and explores the characteristics of echo questions.Through data analysis,we find that echo questions used by both doctors and patients have double features of question and repetition:characterizing question with flat or high tones,fully or partially repeating the preceding utterances and repeating different sentence types like declarative,imperative and interrogative sentences.This study has provided a further understanding of echo questions and some implications for doctor-patient interaction.