In this paper, the impact of spillover pools on patent application behavior of firms in Japan was analyzed empirically using firm-level data from the Survey of Research and Development and the IIP patent database. The spillover pools are calculated with technological distance using the Mahalanobis distance considering the complementarity between technologies for each industry, academia and government. The proxy for firm applications is the number of patent applications. The results of the regression on the count data model employed here show that impact of spillover pools on the number of patent application by firm is positive. Spillover pools from industry, university, and national research institute also have a positive impact on the number of firm patent applications. In addition, spillover pools from basic, applied, and development research have positive impacts.