Abstract There are more than 140,000 Small-Medium Business in Taiwan, especially the CEO is always the decision-maker of the entire enterprise. This research is major through the model of ¡uTheory of Planned Behavior, TPB¡v to study the CEO¡¦s intention to e-business in Small-Medium Business. On the other hand, to understand CEO¡¦s intention to e-business is meant to understand the reason of e-business for Small-Medium Business. This research method is in accordance with an exploratory case study, then investigate by verifiable questionnaires. Through 3 internal variables and external variables of TPB model, such as ¡uAttitude toward the Internet-Adoption Behavior¡v,¡uSubjective Norms concerning the Internet-Adoption Behavior¡v , and ¡uPerceived Behavior Control concerning the Internet-Adoption Behavior¡v to understand CEO¡¦s intention to use Internet. Because of the connection between behavioral intention and actual behavior is very closed, it is to use behavioral intention in place of actual behavior to measure actual behavior in TPB model. According to the result of this study, the 3 external variables ¡uImproving Internal Information Sharer¡v,¡uPromoting the Relation with Customers¡v, and ¡uthe Past Successful Experiences¡vis the most important variables to influence¡uAttitude toward the Internet-Adoption Behavior¡v, and the most substantial is¡uthe Past Successful Experiences¡v. Furthermore, the 3 internal variables also connect with ¡uIntention toward the Internet-Adoption Behavior¡v, and the most influence among these variables is ¡uSubjective Norms concerning the Internet-Adoption Behavior¡v. Meanwhile, among 7 significant others, the major connection is between the staff of CEO and ¡uIntention toward the Internet-Adoption Behavior¡v, secondary is customer. Through the conclusion of this research, we expect to offer this data for Small-Medium Business to consult and help them to accomplish in e-business.