Abstract: ［Purpose/Significance］Information awareness can transform passive response into active perception, which fully reflects the characteristics of "quick response" and "foresight" of information. They are interrelated with the research on content evolution in this field. It can provide news idea for deeply understanding the evolution trajectory, inducting the developing laws, and predicting the development trends of this field.［Design/Methodology］By using the bigraphical superposition analysis, eight keywords related to information services were extracted from the Web of Science database, and the literature about information services in all disciplines was obtained as data source. Research hotspots were grouped for different stages according to the bursts, and the laws of discipline evolution were explored with the use of Dual-map and cooccurrence overlay. ［Findings/Conclusion］Correlations of disciplines have been used to depict the paradigm transformation process of research on information service, characteristics at different evolutionary stages have been distinguished, and the evolutionary laws of information services have been extracted. Additionally, the future development trend of information service have been recognized and predicted. 
［Originality/Value］The theory of information awareness has been advanced, and an analyzing system of complex issues has been proposed for information awareness.

Key words: Information awareness, Bigraphical superposition, Graphic information service, Dual-map, Co-occurrence overlay, Burst