During these decades, e-commerce (EC) becomes an exciting and hot research area. To figure out the knowledge mapping of EC and to indicate its research hot spots and trends for future research, this paper made a comprehensive literature review on EC from 1990 to 2017 based on Scopus academic database. Based on the scope of 11669 EC articles, we found that these articles scattered across 1717 different journals while the research output began in 1992, significantly increased since 1997 and was at the peak of publications in 2000. The United States is the country with the most publication and the most citations. Besides, United States, United Kingdom and Canada are the top 3 collaboration cores in EC alliance. According to 18315 keywords from 11669 articles, we explored 7 clusters which represented different research subjects in EC. The contribution of our study is to provide a means to conceptualize and operationalize the coverage of EC. It provides a conceptual framework to organize this vast body of research. This study ends with some discussions and conclusions.