政府在制定政策的過程中，往往會受到利益團體影響。我們藉由 Grossman and Helpman (1994) 所發展的政治獻金模型為架構，討論在國內生產具有負面外部性的情況下，政府決定是否開放具有生產優勢的外國廠商進入本國生產的決策。我們發現開放外人直接投資與否，受到政府對社會福利重視的程度所影響。在政府極端不重視社會福利且生產完全無生產技術外溢時，政府將不會選擇開放國外廠商進入本國投資，而一般情況下，當市場規模夠大且政府重視社會福利有一定程度時，生產時所造成的負面外部性愈大，本國政府將傾向不開放外國廠商進入本國直接生產。 / Since the domestic government can makes its choice between alternative policy instruments to maximize its’ welfare, this paper analyzes how a domestic government makes the policy about foreign direct investment by Grossman and Helpman (1994) political contribution model. It shows that opening FDI or not is affected by the weight that the domestic government puts on the social welfare. We found that domestic government tends not to open FDI when it puts little weight on the social welfare. In this case that the weight and market are large enough, the domestic government tends to open FDI as the pollution externality increases.