緊密都市目的在於都市永續發展，避免都市蔓延，同時健全都市財政，其中服務居民生活與滿足都市產業機能的運輸系統扮演著關鍵角色。本研究藉相關文獻建立衡量都市的緊密指標以及捷運系統與都市發展的關係，而為使指標具較可衡量，將其區分為高度及密度加以討論。續將緊密指標轉換成因子，以台北捷運通車以來相關發展資料為基礎，建立緊密都市與捷運興建的系統動態關係，探討捷運系統對於都市朝緊密化發展的影響。捷運即將於97年開通的高雄市，雖然人口密度及已規劃為都市地區的比率超過台北市，但就都市面積而官高雄市不足台北市的六成，實際都會範疇與人口亦較少，不似台北市有比例極高的遊動工作人口，且高雄市在住宅、商業大樓使用率上的現況皆不若台北市，卻在和有車輛持有率（小汽車加機車）居全國之冠。因此本研究針對高雄捷運完工、通車營運後對都市造成的影響，藉由架構模型進行模擬，並針對其結果提供建議。

The purpose of compact city is focused on sustainable development of city, avoiding sprawl, nod creating healthy finance structure at the same time, so the transportation system serving residents' life and satisfying with industries' utility in the city plays a key role. We built indicators to measure compactness of city and form relationship between mass rapid transit system (MRT) and urban development by referring, and distinguish more measurable indicators into ”high” and ”capacity”. Base on every relative datum after operation of Taipei MRT, we build a system dynamic model between compact city and rapid transit system, switch each indicators of compact to factors, in order to discuss the impacts on a city developing toward compact by MRT. Kaohsiung city, building a rapid transit system now, has higher population density and more proportions of planned urban division than Taipei, but has less population, moving and commuting people, urban square measure, and utilization rate of residential and commercial buildings. Even the vehicle-ownership rate in Kaohsiung is higher than whole country. Thus land use in Kaohsiung metropolitan after completion of the MRT is forecasted by the model, how to deal with building a sustainable relationship between Kaohsiung MRT and compact land development toward a compact city is discussed.