The author tries to develop and implement a web-based Project Cost Integrated Management System (WPCIMS) in China. The targets, the Cost Breakdown Structure (CBS) and its code system, the functional planning, the framework and the technical index of the WPCIMS were presented firstly. Then, experimental implement of this developed system were put forward in 3 A/E/C project. Finally, an empirical interview survey targeting the project managers of the studied 3 cases was carried to estimate its implement performance. Results show that the acceptance and implement of the WPCIMS can significantly improve the performance of the project cost control, and successful implementation of the WPCIMS, in terms of leading to better outcomes for the A/E/C project, Coordination improvement among participators and Reduction of contract disputes, etc, is not simple a matter of introducing the system into an project organization. Instead, it must be associated with overall project management approaches such as a suitable organization mode, an appropriate system, the standard workflows, adequate personal trainings and even a coordinated project management philosophy.