In the field of philosophy, "epistemology" is meant to explore the ways people acquire knowledge, that is, finding out what are the sources of the faiths of human beings-- justification. Education researches consider it as the questions to judge the true "know", to understand what learners have absorbed in mind, and to know how to testify their understanding. Therefore, epistemology has evolved with education researches of modern times. On 20th century, positivism has gradually taken the leading role in research field. And not only does it bring about great influences in natural sciences, but also in social sciences concerning culture, philosophy, politics, and psychology. Positivism tends to examine the whole world with the naturalistic modes, employing the "empirical-analytical" method to describe, explain, predict, and control every phenomenon. However, positivism bas been encountering the challenges and doubts from the outside world at the same time. This study plans to review both the historic and the theoretical background of positivism in the view of epistemology. Furthermore, it tries to know more about "the ways to get acquired" and discuss the future implications of research in education, in order to clear up the following important questions: 1. The historic background of positivism and its relationship with epistemology. 2. The impacts of epistemology of positivism on research methods in education. 3. The examination and reflection about research methods in education.