城隍神是傳統中國社會最重要的信仰之一，長期以來，城隍神一直被視為「民間」信仰，然而，亦存在一久懸未決的問題，即：何以城隍神很早便有濃厚的官方色彩，其神格亦具鮮明的官僚化特徵？本文著眼於城隍信仰和地方官府的關係，重新梳理宋世以前此一信仰擴張的歷史，並試圖回答此一問題。本文首先指出城隍神信仰兩階段的擴張現象：此一信仰首先於吳越普及化，故盛唐、中唐之際若干官吏因參與地方官府祭祀活動，質疑祭祀城池守護神於禮無據。其次，從中唐至唐末，信仰進而擴及天下。此時人們對城隍立祀的認知也出現變化：從最初欲尋求可以守護城池的英雄人物神，轉為奉祀某種具有守護城池職能的神祇。這解釋了為何某些地區的城隍神面目清楚，且歷久不變，某些地區則否。在信仰新一波擴及天下的過程中，城隍的神格出現日益專業化、官僚化的特徵，且淡化了這些地區信仰和地方的連繫，神祇的面目也轉趨模糊化。最後本文也考慮了城隍信仰擴及天下和地方官府立祀的可能關係。此時城隍信仰的發展，出現若干新趨向：如納入地方官府祀典，出現行政都邑守護神的形象、神格官僚化特徵，以及和地方官對等而治，節制境內山川的神格等等。這些新變化也佐證了各地官府組織，可能是城隍信仰普遍建祀的關鍵力量。

Belief in the city-god was among the most popular religious expressions in traditional Chinese society. It has long been viewed as a kind of ”folk” belief. Yet the question remains why practices surrounding the city-god seemed bureaucratic and how it displayed an obviously bureaucratic image even in its early period. This essay explores the myth of the city-god by reconsidering the history of its spread before the Song period, focusing on its relationship with local government. This article proposes that the spread of city-god worship underwent two phases: first as it was popularized within the area of Wu-Yue through the high Tang to the mid-Tang some officials participated in local sacrificial activities in honor of the city-guarding gods but still doubted if there was any justification for the sacrificial tradition. Then from mid-Tang to the end of the dynasty, the worship of the city-god spread rapidly all over the empire while the popular view changed from seeking an apotheosized heroic personality who could guard the city to the pursuit of any god with this function. This explains why in some areas the original identities of city-gods were clear and remained unchanged through time, while the identities of the gods changed in other areas. In this second phase, there was a blurring of the city-god's profile as it appeared more specialised and bureaucratic, and its ties to the local area weakened. The article also suggests a possible link between the spread of belief in the city-god and the sacrifices to it by local governments, as new trends emerged in its development in the Tang dynasty. Its inclusion in the local sacrificial convention, its image as a city-guarding god, and its bureaucratic features to co-govern the area with local officials: these trends suggest that local governments played a critical role in the popularization of city-god belief.