：志愿者在美国图书馆服务和建设中发挥着重要的作用。文章通过对美国城市图书馆委员会（UCC）的152所城市图书馆进行调研，探究其当前志愿者服务机制模式，发现美国城市图书馆的志愿者服务具有以下特点：志愿者规章制度信息易获取、政策信息公开程度高、申请方式主要分为三类、招募志愿者具有标准招聘流程、年龄要求趋于年轻化、志愿者时长规定可商榷以及志愿者技能与经验要求宽松。虽然美国城市图书馆已形成规范系统化的志愿者服务机制模式，但还面临着许多亟需解决的现实挑战，通过对这些问题的分析，对我国志愿者服务建设发展有实践启示。

Volunteers play a vital role in the service and support of American libraries. Through an investigation of 152 American urban libraries in the authoritative American Urban Library Committee (UCC), this research explores the current model of volunteer services and their characteristics. The results indicate that rules and regulation information for volunteers to work in the US urban library is easy to obtain, public policy is openness, application methods can be divided into three categories, and the recruitment process is also coherent across these libraries. The research also finds that the libraries tend to hire younger volunteers, and most of them have little or no requirements for skills and work experience, furthermore, the working hours can be negotiated. Although the American Urban Libraries have formed a standardized and systematic volunteer service model, they still face many practical challenges that need to be solved. Hopefully, these findings and analysis can be exploited in future works as a useful source of information to guide volunteer services in libraries in China.