Abstract: Policy implementation is the pivotal part to policy process. According to Smith's policy implementation process model, ideal policy, implementation institution, targeted group, and policy environment are the key factors for whether policy implementation is success or not. The dilemma of policy implementation for street children mainly is the simple assistance content and out-dated assistance mode. In line with Smith's policy implementation process model, scarcity of ideal policy documents, insufficiency of effective abilities for implementation institution, high complexity of targeted group, and poor policy environment all contribute to the dilemma of policy implementation for street children. To improve the policy for street children assistance, it is suggested that operability of policy documents be enhanced, ability of policy implementation institution be improved, assistant to targeted group be categorized, and friendly policy environment be created.