The study explores the impacts of regional knowledge endowment and innovative linkages on the quantities of firms with R&D activities and the interaction between innovative linkages and technological gap based on inter-provincial panel data of China. The conclusions suggest that heightening regional knowledge endowments and narrowing technological gap have positive impacts on the quantities of firms with R&D activities, but innovative linkages show distinct influences conditioning by its types only in innovation-followed regions, inter-firm linkages have negative impacts, and industry-university linkage show positive impacts; the regional technological gap shows negative interaction with inter-firm linkages, but positive interaction with industry-university linkages.