The purpose of this study was to review the current state and characteristics of instruments used to assess individual understanding of the nature of science (NOS). This study conducted a series of content analyses of the articles published in a total of seven Korean and international journals from 1990 to 2009. A total of 99 research papers and assessment tools were categorized according to their features such as item type, the method of development, philosophical perspectives and others. So, evaluation domains of the instruments were also compared with the features of the NOS endorsed in some standards science education documents internationally well known, such as Benchmarks for Science Literacy (AAAS, 1993), National Science Education Standards (NRC, 1996). It was found that VNOS was the most frequently used instrument used for the last 20 years. There was a difference between characteristics of instruments used in Korean journals and these in international journal, such as philosophical perspectives, item type. Moreover, the results showed that there were only a few of instruments to ask about ethics of scientists, significance of science process skill and the context. NOS instruments focused only on limited aspects of NOS emphasized by the standard documents.