臺灣過去一直維持著北高南北兩直轄市並立的局面，然隨著北部「新北市」、中部的「臺中市」、南部之高雄縣市、臺南縣市合併升格為「高雄市」、「臺南市」，五直轄市成形逐漸確立了北、中、南部三大都會區並立的態勢。本文欲從國土規劃之角度，分別就全國、區域、地方階層探討五直轄市升格後對於跨區域整合及空間發展將形成之新局面及其所帶來之影響。發現升格後對於平衡北、中、南區域間發展、地方政府體系的有效運作等有所助益；反之，財政資源集中於五直轄市則會加劇與其他縣市間的城鄉落差等。 Taiwan used to be in the situation of Taipei & Kaohsiung City exist side by side, but after the promotion of five special municipalities, beside the former two, Taipei County became New Taipei city. Greater Taichung City as the result of a merger of Taichung City & Taichung County, in the middle Taiwan; Tainan a merger of Tainan City & Tainan County; Kaohsiung a merger of Kaohsiung City & Kaohsiung County in the southern Taiwan. The situation of the coexistence of three regions, Northern, Middle & Southern Taiwan is gradually appearing. This paper deals with the cross-region integration & governance from the view of national spatial planning after the operation of five special municipalities, discussing the effects caused by the operation of five special municipalities in the level of national, regional & local apart. It shows some consequence such as balancing the regional development gap between the three regions, Northern, Middle & Southern Taiwan, & helping the smooth functioning of local government administratively also; on the contrary, the high concentration of fiscal resource into the five special municipalities can occur the development gap with other local governments.