都會區的人口分佈形態和演化趨勢，對政府政策的釐訂有著重要的意義。都會之郊區化已是全球非常普遍的現象，文獻指出居民所得和交通成本對都會人口郊區化有著重大的影響。本研究利用一個簡易的都會模擬模型(urban-simulation model)，以台北為例來探討此一重要議題。 研究指出：多核心模型較傳統的單核心模型更能符合晚近的都市結構。本研究採雙核心(市中心和環狀副都心)模型探討所得和交通成本對都會人口分佈的影響，除了下列二項主要不同點外，遵循Alonso模型的假設：(1)交通整體的便科性，而不只是通勤成本，影響住屋選擇；和(2)都會中心和副都心除空間分布上的差異外，都會有中心相較於副都心還有著因歷史發展、規模經濟等因素而來的相對優勢。模型中的主要變數包括﹕所得、交通財單價、人口數、市中心的相對優勢、及土地偏好等。 人口密度梯度(population density gradient)常用為都會人口郊區化程度的指標。本研究針對一個概念性的台北都會區，透過所得彈性和交通成本彈性的計算，以推估和探討居民所得和交通成本因素對都會人口郊區化的準動態影響，期望對未來台北都會區人口分佈的可能發展有更多的了解。

　　　　　Suburbanization is a world common phenomenon in the past several decades and studies on this subject usually have important policy implications. Literature reviews show that rising income and improved transportation system are two most significant driving forces for suburbanization. In this study, the author extends William Alonso's model to study the suburbanization of Taipei. The basic layout is that a city with fixed boundary locates at a featureless plain, and has a point-like central business district (CBD) and a circumferential suburban business district (SBD). The relative frequency of trips to each district is dependent on the population ratio of the inner city to the suburban area, the degree of advantage of the CBD, and residential location. Simulation results of this study show that the magnitude of income elasticity and transportation cost elasticity of the population density gradient for 1997 Taipei are about 1.2. The author hopes this study can shed more insight on the evolution of population distribution of Taipei.