Association analysis of researcher’s usage pattern of technical information is useful to find technology convergence characteristics, and the collection of utilization logs of information service system for information use and search is getting easier these days. There has been emphases on the importance of using them as source data for utilization behavior analysis. In this paper we try to figure out the convergence technology fields using analysis of utilization pattern of academic papers or patents information which used together by researchers. Korea Institute of Science and Technology Information is operating National Digital Science Library of Korea (NDSL), a website that provides scientific and technological information services. NDSL is the largest website in Korea that constructs and provides information on academic papers and patents. This study deduces convergence utilization between technologies by analyzing the relationship between the fields of information utilized simultaneously through an analysis of the usage sessions of NDSL. Through association analysis we identified the relations of technology fields. From the data analysis of 260,751 cases of utilization logs of information service, significant relation rules was identified such as the academic papers of ‘Mechanics’, ‘Business and economics’, ‘Sociology’ and ‘Information’ fields were used together or the patents of ‘Performing operations and transporting’ and ‘Chemistry’ fields were used together. Concerning relationship analysis, research was conducted on the simultaneous appearance frequency on the national standard classification of science and technology of Korea for academic papers and IPC sections for patents. As an analysis method, in order to discover the association rule in the if-then form, the apriori algorithm function of R language was used. The performance the analysis of 260,751 cases of data using R was 0.15 s.