都會區的人口組成複雜，來自不同種族、文化、性別、階級、年齡、國家、政治團體與宗教的成員聚集於此，這些成員間的身份差異構成了都會區各式各樣有形和無形的多重邊界。而都會教育的課程與教學如何賦予未來公民批判與轉化的知能，以跨越、解構與不斷重塑既有的邊界，誘發與促動這些邊界的變化，解放因身份差異造成的壓抑權力關係，進而以多重形式的差異重建民主的公共生活，將是都會學校的核心工程。因此，本文運用Giroux的邊界教育學觀點作為理論基礎，分析都會區後塗鴉文化之跨越、解構與重構邊界的特性，並探討都會教育如何運用後塗鴉文化跳脫既有課程與教學的主流框架，以不同方式解讀並創造文本和歷史，挑戰、解構並重塑邊界。

Urban population is composed of people from diverse races, cultures, genders, classes, ages, nationalities, political groups, and religions. The multiple differences of identities between populations form a wide range of tangible and intangible borders. It is an essential mission for urban schools to design curriculum for equipping future citizens with critical and transformative competences to transfer, deconstruct, and reconstruct existing borders, to induce and facilitate the shift of borders, to liberate the repressing power relations derived from group differences, and to reconstruct a democratic public life with respect of multiple group differences. Hence, this article adopts Giroux's viewpoints of border pedagogy as theoretical basis to analyze the nature of urban post-graffiti culture, i.e. border crossing, deconstruction and reconstruction. It also attempts to illustrate how post-graffiti culture can be employed in urban education to devise alternative ways of reading and creating texts and history beyond present mainstream curriculum and instruction.