The rapid spread of technologies involving the application of "Genetic Modification (GM)" raised the need for science communication on this new technology in society. To consider the communication on GM in the society, an understanding of the current mass media is required. This paper shows the whole picture of newspaper discourses on GM in Japan. For the Japanese public, newspapers represent one of the major sources of information on GM. We subjected the two Japanese newspapers with the largest circulation, the Asahi Shimbun and Yomiuri Shimbun, to an analysis of the full text of approximately 4000 articles on GM published over the past to perform an assessment of the change of reportage on GM. As for the most important results, our analysis shows that there are two significant shifts with respect to the major topics addressed in articles on GM by Japanese newspapers.