The aim of this study is to examine the development of science concept in Turkey. It is seen that the historical process of science concept in Turkey has developed within two stages. The first setting is the later stages of the Ottoman State and the Republican Era, at which time positivism was prevalent as noted in the objectives of the national science curriculum. The second stage includes the period starting from 2004 to the present when the effects of postmodern epistemology started to partially be seen with the initiation of the new elementary curriculum based on a "constructivist approach". Positivism entered into the Ottomans during the 19th century and it affected especially the school programs. During this process, at first the positivist/modernist paradigms and later on the postmodernist paradigms affected the curricula scientifically and epistemologically. This study was based on document analysis approach. The documents used in this study were selected to represent the science curriculum of 1913, 1924, 1926, 1930 and 2004 programs. The document analysis revealed that the remained effects of positivism is observed until 2004 program. Even though, there is no deviation from the basic paradigm regarding scientific understanding until the 2004 program, the 2004 program reflects a fundamental break from the traditional approach to constructivism.