Abstract: In the information age, amounts of semi-structured or unstructured texts in microblogs, forums and newspapers are collected but are not well utilized. However, with the development of text mining technologies, it is the time to discover hidden value of text data for public health. This paper briefly introduces the concept, characteristics and data sources of textual analysis. Seven applications of textual analysis in the field of public health are then demonstrated, including: disease surveillance and forecasting, public opinion, attitudes and needs, assessment of the effects of health-related interventions, health-related behavioral characteristics and influencing factors, mental health, health policy and management, and health education.