Keywords of academic papers are jargons shared within a research domain as well as a summary of the contents. However, the increasing popularity of the interdisciplinary research in academia in recent years opened a possibility that the choice of keywords would be no longer confined by the traditional domain boundaries. In order to investigate the evolutionary trends of keyword-sharing groups in academic publications, we applied three types of Social Network Analysis methods on the papers in the Computer Science domain collected from the Libra database. Particularly, papers published in 5 different time periods from 1970 to 2010 were targeted to show the change of keyword networks over time. The analysis results confirmed the increasing tendency in the keyword network to be absorbed by one big agglomerated cluster over time. As a result, the gatekeeper- or liaison keywords seldom exist in later times but coordinator keywords became majority.