行道树是公路建设中的重要组成部分，它具有防护林，经济林等林种的功能，它不仅能美化环境，并且还能对自然环境起控制作用。搞好规划设计，根据不同道路和环境合理配置树种，就能使行道树发挥最大的生态、社会、经济效益。 Road tree is an important part of highway construction. It has the functions of shelterbelts, economic forests and other forest types. It can not only beautify the environment, but also play a role in controlling the natural environment. Do a good job of planning and design, according to different roads and environment reasonable allocation of species, will be able to make roadside trees to maximize ecological, social and economic benefits.