The purpose of this research was to analyze importance of key word on the journal of the Korean institute of plant engineering (JKIPE). We collected 857 key words in each paperson JKIPE from 2009 to 2013. Social network analysis is one of good method to analyze the importance of key words. To find the most important key word, we used the degree centrality, the betweenness centrality, the closeness centrality and the proximity prestige centrality on key word.