Purpose:The aim of this paper is to discuss how the keyword concentration change ratio (KCCR) is used while identifying the stability-mutation feature of Web search keywords during information analyses and predictions.Design/methodology/approach:By introducing the stability-mutation feature of keywords and its significance,the paper describes the function of the KCCR in identifying keyword stability-mutation features.By using Ginsberg’s influenza keywords,the paper shows how the KCCR can be used to identify the keyword stability-mutation feature effectively.Findings:Keyword concentration ratio has close positive correlation with the change rate of research objects retrieved by users,so from the characteristic of the stability-mutation of keywords,we can understand the relationship between these keywords and certain information.In general,keywords representing for mutation fit for the objects changing in short-term,while those representing for stability are suitable for long-term changing objects.Research limitations:It is difficult to acquire the frequency of keywords,so indexes or parameters which are closely related to the true search volume are chosen for this study.Practical implications:The stability-mutation feature identification of Web search keywords can be applied to predict and analyze the information of unknown public events through observing trends of keyword concentration ratio.Originality/value:The stability-mutation feature of Web search could be quantitatively described by the keyword concentration change ratio (KCCR).Through KCCR,the authors took advantage of Ginsberg’s influenza epidemic data accordingly and demonstrated how accurate and effective the method proposed in this paper was while it was used in information analyses and predictions.