Expectancy Theory(Vroom, 1964), saying that all behaviors of an individual depend rationally on the perceived likelihood and the desirabilities of outcomes, has been one of main theoretical frameworks(Ambrose and Kulik, 1999) explaining human motivations in real job settings in the past 20 years, and currently is coming newly into the spotlight as practical and cognitive behavioral theory to induce successful activities (Edelman, Brush, Manolova, and Greene, 2010). Expectancy Theory has an efficient architecture capable of identifying easily individual`s subjective decision making processes by effort-performanceoutcome frame and a third party`s intervention or socio-economic environment creation in the processes. In this study, the effects of entrepreneurial expectancy on start-up outcome satisfaction mediated by the start-up activities and growth intentions was researched. For the purpose of this study, a questionnaire survey was conducted of 286 venture and small/medium business entrepreneurs in Seoul and the metropolitan area, South Korea, and their responses were empirically analyzed using structural equation modeling. The results of this analysis are summarized as follows. First, entrepreneurs believe the likelihood of successful start-up will increase if they make the best use of their own skills, expertise and experiences and support organizations make efforts to improve entrepreneurs` abilities and problem-solving strategies. Second, entrepreneurs perceive start-up activities and growth intentions as one of important means to achieve their own goals in life. Third, entrepreneurs consider as important entrepreneurial goals, the six elements of start-up outcome satisfaction including self-realization, financial success, independence, innovation, role, and recognition-especially, self-realization and innovation. This suggests advanced country type entrepreneurial motivations, as commonly seen in the course of transition from factors-and efficiency-driven economy type start-up to innovation-driven economy type start-up. Finally, it was found that there are predominant preferences of opportunitybased start-up pursuing firmly growth, to necessity-based ones. In this study, it was ascertained that study scope could be expanded from the field of organizational behavior regarded conventionally as the exclusive area of Expectancy Theory, to the field of start-up activities in which planned behaviors are emphasized. In addition, it paves the way to provide necessary information for entrepreneurial support organizations to propose effective alternatives for start-up and growth supports in consideration for individual`s abilities, desires, values and circumstances in the process of motivation. The author earnestly hope that this study makes a great contribution to the both academic development and the practical improvement, in the light of combining start-up activities with the construct of Expectancy Theory that show the processes in which entrepreneurs make start-up related decisions on the basis of entrepreneurial likelihood and start-up outcome satisfaction, the parties concerned in start-up intervene appropriately during motivation, and favorable circumstances for start-up are created.