Abstract: On the background of some ore concentration plant, the dynamic cost control system structure based on the three layers structure of ERP/MES/PCS was presented with the support of network, database and information technologies. This system is objected for production process, collects cost data of all working procedures according to the certain cost center, monitors cost indexes, and completes dynamic cost accounting. Using the model to decompose, forecast and analyze cost, the system implements the dynamic cost control and the integration of the information flow, material flow and fund flow. The system was put in practice and great effect was obtained.