The paper introduces a novel real-time interactive LBS system, which can be applied to large-scale smart parks such as tourist resorts, Expos and campuses. Compared with the existing systems, some new functions in the proposed system are introduced. The system is composed of Service Center and mobile client. The Service Center provides services such as routine planning, congestion avoiding, announcements publishing and so on. The mobile client is capable to send various kinds of pre-defined requests to the Service Center and concurrently process real-time responses. The prototype system is illustrated to prove the usability and practicability.