<p><em>The emergence of new trends in technology, social and economic have a positive impact on the growth of e-commerce in Indonesia. Based on research reports from various research institutions in the world shows that the contribution of the transaction value of retail e-commerce to the national retail revenues in Indonesia is still relatively small, but has significant growth and has huge potential in the future. Lately the number of micro, small and medium enterprises (MSMEs), which entered the e-commerce business by opening an online store is increasing. However, based on the results of the pre-research shows that only a few online stores that have a superior business performance. Referring to the literature, shows that business performance is the result of a competitive advantage that can be built through the development of core competency. The components of this core competency, is different for each industry. The results of exploratory research showed that core competency for e-commerce online store is comprised of: entrepreneurial orientation, dynamic capability and the formation of strategic alliances.</em></p><p><em>            This study aimed to assess the effect of entrepreneurial orientation, dynamic capability and strategic alliances formation either simultaneously or partially on competitive advantage and its impact on business performance. The unit of analysis in this study is online stores company in e-commerce, while the unit of observation is the leader of online stores in Jakarta. This study uses Mix Methods Research with Sequential Transformative Strategy</em> <em>using instruments i.e exploratory, descriptive, explanatory and grounded research.</em></p><em>            From the results of the study revealed that the level of entrepreneurial orientation, dynamic capability, the formation of strategic alliances, competitive advantage and business performance online store in Jakarta is still less superior. The third variable of core competency entrepreneurial orientation, dynamic capability and the formation of strategic alliances have no direct impact on business performance online shop but indirect effect through competitive advantage. Furthermore, from the grounded research revealed that there are five important external factors that contribute to increase the productivity of business performance, namely: Government, Marketplace e-commerce provider, Internet access provider, courier service providers and non-governmental agencies. From the findings above, then built the key success factor for e-commerce frameworks.</em>