Within modern society, digital signage, billboards, and signboards have been widely and successfully applied for sending various information and advertisement. However, how to evaluate the dispatched benefits is an extremely important issue for business owners. In order to tackle this problem, this paper proposes an effective evaluating system for digital billboard audiences. Via the build-in front-end camera, individual audiences' watched dates, time periods, halted durations and locations are able to be precisely recorded, and through these collected data the proposed evaluation system can provide statistical information to the authorized personnel for further assessing the relative benefits of specific billboard.