本研究建立一個賽局理論模型，探討廠商進入海外市場之模式的抉擇與研發支出以及產業內廠商異質性之關係。本文理論研究顯示，高科技產業廠商以及研發能力較高廠商較可能進行海外投資以逃避進口關稅。此外，研發外溢效果較高以及直接設廠相對於跨國購併的固定成本較低時，廠商將會選擇以直接設廠模式進入國外市場。本文利用台灣製造業廠商追蹤資料的實證研究亦顯示，智財權榜護程度較高之國家，廠商較願意採取併購模式進入該市場。此結果與本文理論預期一致。此外，本文發現，廠商對外直接投資對其研發支出有正面效益，惟對於其技術效率則無顯著影響。至於對外直接投資模式之差異對投資廠商之研發支出以及技術效率的影響均無顯著不同。 This paper investigates the relationship between multinational firms’ choice of entry modes of international expansion and their R&D activity under firm heterogeneity by developing a game-theoretical model to derive testable hypotheses. Our model predicts that a firm belonging to an industry with higher R&D productivity or having a higher capability in R&D activity tends to undertake FDI to “jump the tariff”. In addition, facing relatively high R&D spillover effects and relatively small difference in costs between cross-border M&A and green?eld FDI, a multinational firm tends to choose green?eld investment rather than cross-border M&A. Empirical evidence from a firm-level panel dataset on Taiwanese manufacturing firms indicates that multinational firms tend to invest into a country with higher intellectual property right protection via cross-border M&A strategy, which is consistent with our theoretical prediction. Our empirical results also reveal that while a firm’s foreign direct investment is positively related with its domestic R&D expenditures, the relationship between a firm’s foreign direct investment and its technical efficiency is not significant. In addition, the impacts of different entry modes on a firm’s domestic R&D or technical efficiency are not significantly different.