This paper expanded the usefulness of technology relation analysis by applying to R&D activities of Korea Gas Corporation (Kogas) at the corporate level. Technology relation analysis has been applied to assessment of R&D investments in telecommunication and construction industries in Korea. As empirical findings, technology map and technology spillover matrix of Kogas have been derived by technology similarity analysis. It has bee found that various useful information for R&D assessment could be acquired from the technology relation analysis at the corporate level.