本硏究主要進一歩將葉金成、張清興〔l]之論文中，僅具單向因果關係的假定，放寬為 具雙向的因果關係，並利用多元時間序列分析，探討國防支出與國民所得間的因果關係，硏究 結果顯示國民所得顯著影響國防支出，而國防支出對國民所得之影響未逵顯著水準。本硏究除 建立多元時間序列模型，來探討這二個變數間的因果關係之外，並將硏究結果與該論文相互比 較，硏究結果發現國防支出對國民所得之影鹡未達顯著水準之結論與該論文不同。

The purpose of this study is to explore the two-way causal relation between the Defence Expenditure (hereafter DE) and the GNP of the Republic of China, by multiple time series analys. It is a further research of comparing with the hypothesis of one-way causal relation in the thesis by Yeh, C.J. & Chang, C.S. (1). This study indicates that the GNP has an effect on the DE, but that the effect of the DE on the GNP is not significant. In addition to constructing the multiple time series model to explore the causal relation of the DE and the GNP, the result of this paper, the effect of the DE on the GNP is different with Yeh’s.