This study was carried out to examine the tendency about the relative importance of STS education of the 6th and 7th primary science curriculum. The results of the research are as follows. Primary science textbooks in the 6th curriculum, average 13.3% of the total pages was assigned to STS contents but it is increased to 24.2% in the science textbooks of the 7th curriculum. STS constituents of the 6th primary science textbooks come out orderly applications of scientific knowledge(47.1%), relevance of a community(40%), social problems and issues(11.8%). Of the 7th science textbooks, the contents about applications of scientific knowledge amount to 67.1% of the total STS constituent and relevance of a community(32.2%) rank behind it. The contents of other components are not enough. The 6th science textbooks contents about the effect of technological development amount to 35.3% of the total STS subject area, and environmental quality(20.0%), natural resource(15.2%), energy(11.8%), sociology of science(11.8%) ranks behind it. In the 7th science textbooks ranking is the effect of technological development(42.3%), natural resource(17.3%), energy(12.5%), sociology of science(12.5%), environmental quality(20.0%). There are few contents about population, human engineering and space research and national defense in the science textbooks.