由於估計直航後運輸成本變化的準確性，對以經濟計量模型估算直航對於臺灣經濟影響的結果，有很大的影響，因此估計直航後運輸成本的變化便顯得相當重要。惟文獻上對於直航可節省成本的估計差異甚大，故本文擬依兩岸現況估算直航可節省成本的合理數據。文中針對臺灣與大陸華北、華中、華南三大定期航線進行分析，以從事於該航線之最通用的船型為主力船舶，並以此做為成本計算之基準。初步推估得兩岸直航後，華北、華中、華南三大定期航線每年可節省總運輸成本，約為4080萬美元。

Under the constraints that there is no direct shipping link across Taiwan Strait, those ships undertaking cross-strait operations have to call via a port in the third area. However, it has been claimed that skipping the third-area port would save extra cost. What would be the influence if Taiwan government lifts the ban on direct trade and shipping? Some papers have evaluated the economic impact of cross-strait direct shipping, but they have difference findings regarding the extra cost. In this paper, we try to estimate the extra cost, in order to have an explicit understanding of the effects of cross-strait shipping policy.