國防預算與國防戰略規劃與兵力结構有直接的關聯。過去學者對於國防預算的研 究，曾出現國家經濟能力觀點、軍事威脅觀點、政治分配觀點、整體理性觀點及組織程 序觀點等五種不同的研究取向；本研究嘗試整合過去相關研究的觀點，對影響國防預算 變動的因素進行全面性的因果關係檢視。研究結果顯示，國防預算的變動仍以滿足現有 戰力的内在財務需求驅力為其主要依據；其它外在的環境因素，包括軍事威脅層面與供 给層面的因素，都僅扮演著預算修正與調節的間接角色。而以個別因素的影響性來看， 也發現了過去的大陸國防預算、過去的中央政府總預算以及過去的GDP，對國防預算的 解釋能力，都不及國防預算本身的解釋能力。而就整體模式的解釋能力判斷來看，過去 學者對於國防預算各種切入觀點的討論，實已有效掌握國防預算變動的可能變異來源。

Defense budget(DB) is associated directly with Defense strategic planning and force structure establishment, and prior studies have demonstrated different concerned to approach DB. In this study, we integrate different point of view into a comprehensive one in order to examine the causality of these constructs with DB through VAR model. Results showed that financial demand from within in Defense department was the most influential driving force in explaining the change of annual DB, while the military threat of Mainland China and Defense financial supply were played secondary roles as the modification and reconciliation factors in DB formulation process. In comparing of the relative explanatory power of constructs, previous DB was found to be the most influential variable over the influence of China Mainland's DB, government budget and GDP. After examining the explanatory power and the predictive validity of VAR model, we also believe that prior researches on DB of different aspects have effectively captured the source of variance that associated with the change of annual DB.