中文摘要：

本文基于已有的研究讨论了城市活力的影响因素，提出人口密度和到中心城区的距离是决定城市新区发展绩效的关键因素。本文的政策含义是，违背经济规律，建设低密度的社区，或者将城市新区建设在远离中心城区的地方，将降低城市发展的活力。

英文摘要：

Based on existing studies, this paper discussed the factors affecting urban vitality. It emphasized the fact that population density and distance to urban center determined the performances of the newly-developed regions of a city. The implication of this paper is that lowdensity communities or new towns far away from the city center are not consistent with market forces and will reduce the vitality of the city.