Purpose: This study attempts to investigate how a user’s search behavior changes in the exploratory search process in order to understand the characteristics of the user’s search behavior and build a behavioral model.Design/methodology/approach: Forty-two matriculated full-time senior college students with a female-to-male ratio of 1 to 1 who majored in medical science in Jilin University participated in our experiment. The task of the experiment was to search for information about “the influence of environmental pollution on daily life” in order to write a report about this topic. The research methods include concept map, query log analysis and questionnaire survey.Findings: The results indicate that exploratory search can significantly change the knowledge structure of searchers. As searchers were moving through different stages of the exploratory search process, they experienced cognitive changes, and their search behaviors were characterized by quick browsing, careful browsing and focused searching.Research limitations: The study used only one search topic, and there is no comparision or control group. Although we took search habits, personal thinking habits, personality characteristics and professional background into account, a more detailed study to analyze the effects of these factors on exploratory search behavior is needed in our further research.Practical implications: This study can serve as a reference for other researchers engaged in the same effort to construct the supporting system of exploratory search.Originality/value: Three methods are used to investigate the behavior characteristics during exploratory search. Purpose: This study attempts to investigate how a user’s search behavior changes in the exploratory search process in order to understand the characteristics of the user’s search behavior and build a behavioral model. Design / methodology / augach: Forty-two matriculated full-time senior college students with a female-to-male ratio of 1 to 1 who majored in medical science in Jilin University participated in our experiment. The task of the experiment was to search for information about “” the influence of environmental pollution on daily life " The research methods include concept map, query log analysis and questionnaire survey. Findings: The results indicate that exploratory search can significantly change the knowledge structure of searchers. As searchers were moving through different stages of the exploratory search process, they experienced cognitive changes, and their searched behaviors were characterized by quick browsing, careful browsing an d focused searching.Research limitations: The study used only one one search topic, and there is no comparision or control group. Although we took search habits, personal thinking habits, personality characteristics and professional background into account, a more detailed study to analyze the effects of these factors on exploratory search behavior is needed in our further research. Practical implications: This study can serve as a reference for other researchers engaged in the same effort to construct the supporting system of exploratory search. Origin / value: Three methods are used to investigate the behavior characteristics during exploratory search.