This year, 2013, is the 20th anniversary of e-business. In the past 20 years, e-business has played an increasingly important role in both academic and professional communities. Additionally, thousands of e-business articles have been published each year since the turn of the century. We have a sufficient period and sample size to conduct impact analysis in e-business research. However, very few studies have conducted such an analysis. Examining patterns of research impact in a field is important for assessing the state of that field – its emphases, contributions, and opportunities for further development. This study takes e-business adoption research as an example, uses citation data, and conducts impact analysis to serve four goals: identify influential e-business adoption research, describe patterns of impact, explore potential factors in citation change, and compare accumulated citations and citation change. Overall, this study deals with both e-business and impact analysis, and therefore contributes to both areas.