我國財政部去年通過稅法修正，為加強清理欠稅，將持續追查欠稅人與關係人資金流向，先針對欠稅金額新台幣一千萬元以上欠稅大戶，延長追稅期五年，以確保國家租稅債權，有關政府延長核課期間對於代表性納稅人逃稅行為之影響為何，本文以跨境逃稅的宏觀思維與現實國際經濟狀況，考量有關本國與境外之稅率差異，代表性納稅人為自身租稅規劃，考量逃稅被處以補稅及罰款以及考量境內所得移出至境外存在運送成本之情況下，將境內所得移至海外，存在核課期間情況下，建立納稅人海外所得稅基侵蝕租稅模型，探討納稅人將境內所得逃至海外以規避稅負，對納稅人跨期選擇與稅基侵蝕行為之影響分析，提出學理上之可行之建議。

Concerning the influence of the government tax levy on tax evasion of representative taxpayer during the course of assessment period. This paper takes the macroscopically thinking of cross-border tax evasion and the actual international economic conditions into consideration. The tax rate differences between domestic and overseas are considered. The representative taxpayers plan their own taxation. Tax evasion is subject to refunding and fines and considering the removal of domestic income from shipping costs that exist outside the country. If domestic income is transferred overseas and there is a assessment period, taxpayers' overseas income tax erosion model will be established. The domestic proceeds to escape overseas to avoid tax burden, taxpayer intertemporal choice and tax base erosion analysis of the impact, put forward the theory feasible advice.