Dual-use technology, upon its effective development, can be a highly efficient technology that may be utilized for both achieving industry competitiveness and building National Security. Although research needs for such development methodology and call for corresponding efforts have long been proposed, actual outputs have not reached its desired level. Hence, this paper aims to provide more concrete and quantitative process in technology planning used to activate development of dual-use technology, considering dual usability and transferability of such technologies. In such effort, we propose use of patent analysis and the Analytic Hierarchy Process (AHP) for determining priorities for spin-off defense technology. First, the necessity of R&D and potential spin-off are measured based on patent information. Second, the necessity of R&D results from a quantitative analysis and the potentials spin-off are derived from analysis of patent citations. Then, AHP is used to calculate the importance of evaluating factors, and to assess alternative scores. Finally, we present the result of spin-off priority. A case study on the Korea defense technology is presented to illustrate the proposed method. We expect this study to make contribution in vision making of the military R&D spending.