<正>城市森林作为城市生态系统的初级生产者，对于改善城市环境质量、保障城市系统的可持续发展具有重要作用。依据“城市度”的变化，城市森林一般区分为市区森林、近郊森林和远郊森林三个部分，每个部分因其特定结构对城市活动产生不同的功能效应。城市林业是研究城市森林生态系统的一门综合性的边缘学科，以便为城市居民提供安全的多种环境和社会效益。笔者分析了城市林业的起源与理论架构，概述了城市林业的研究现状和应用实践，为我国城市林业的学科发展和城市现化代建设提供参考。

Urban forest is usually referred to vegetation growing in urbanized area or areas influenced by urban activities. Generally speaking, urban forest could be divided into such three parts as central urban forest, periurban forest and exurban forest. Urgently demand for trees management and concerning with urban landscape and citizens living quality resulted in conceptual formation of urban forestry based on integration of urban forest and urban ecology since 60s of this century. Urban forestry pays more attention to structure, function, boundary, gradient and linkage of urban forest ecosystem, to ecosystem management, land utilities and spatial distribution of benefits and costs; and to participation and disturbance of mankind. Urbran forestry aims to construct safe, beautifying and effective urban forest so as to improve local environmental quality. Meanwhile, urban forestry tries to provide an ecosystem management approach for dealing with relations of human beings and natural resources, of environmental conservation and developmental construction. Urban forestry makes an attempt to understand social and ecological values and common well-beings characteristics of urban forest. This paper tries to discuss about the principles and practices of urban forestry, and to promote development and application of urban forestry in China.