This paper makes a comparative study on mobile libraries operated by public libraries in Guangzhou,Hong Kong and Macao,focusing on the types and quantities of their motor vehicles,the distribution of theirservice points,the costs and social benefits,and so on. It points out some problems,such as the discontinuity ofmobile library service,the delay of information releasing,and the limited forms of service. It then proposes to givefull play to the rapidness and flexibility of motor vehicles,provide regular service,enrich the forms of service,and try to open new service points.