In this dissertation research project, we try to unravel the black box of learning by entrepreneurial ventures with two fundamental learning dimensions: learning extensity and learning ambidexterity. Learning extensity represents how extensively the entrepreneurial ventures engage in market learning, technology learning, social-network learning and cross-market learning. Learning ambidexterity represents the balance between exploitative and exploratory learning. Through an online survey, we give entrepreneurial ventures a comprehensive exam on their learning with quantified measurement. Concerning the determinants of learning characteristics, we explore a variety of task-related prior experience of the core entrepreneurial team. We found that education and work experience are the main influencers of exploitative learning; while technology experience increases exploratory learning. Interested in the consequences of learning, we examine the relationship between learning and outcome variables including product innovativeness, the degree of internationalization, customer reception and financial performance of the entrepreneurial venture. We found that market learning is the most important type of learning for this group of high technology entrepreneurial ventures, with significant positive influence on product innovativeness, customer reception, and financial performance. Technology learning enhances product innovativeness; social network learning improves customer reception; cross-market learning leads to the accelerated internationalization of the venture. We also found that higher degree of internationalization and better customer reception are associated with better financial performance. Our empirical results show that exploitative learning contributes to financial performance through enhanced customer reception; and exploratory learning contributes to financial performance through accelerated internationalization. Exploratory learning also increases product innovativeness of the entrepreneurial venture. But product innovativeness does not have a direct relationship with financial performance of the entrepreneurial venture.