本文以引力模型來檢驗日本海直接投資(FDI)的決定因素,針對該模型之相關文獻及實證歸納與整理,選擇出GDP乘積、人均GDP差額、地理距離、貿易收支、匯率、開放程度、貿易協定等變數來進行探討,研究期間為2000年至2011年。核心問題為區域經濟整合是否會日本海外直接投資有所助益?文末的主要結論為:其一、匯率的波動和地理距離對於日本海外直接投資的影響不明確。其二、區域經濟整合有助於日本的海外直接投資。其三、日本的製造業投資較接近於垂直型的直接投資;非製造業的投資恐傾向於水平型的直接投資。 This paper applies a gravity model to examine the determinant of Japan’s FDI and covers the period from 2000 to 2011. Also, it reviews the relevant literature on the gravity model, then proceeds to use gravity model with the variables of GDP (Gross Domestic Product), per capital income, distance, trade balance, exchange rate, trade openness, and FTA to do research. The main subject is “Does regional economic integration cause Japan’s FDI?” In conclusion, we found that regional economic integration is positive and statistically significant for Japan’ FDI. Secondly, exchange rate and distance do not seem to matter much for Japan’s FDI. Finally, FDI in manufacturing is vertical type and non-manufacturing sector tends to be a horizontal type.