A system for integration of material costs of a product (1) can calculate material costs of a product according to purchase data, inventory data and material consumption data. The system for integration of material costs of a product is connected to a number of client terminals (3), a purchase management system (6), an inventory management system (8) and a production management system (9) via a network (2). The system for integration of material costs of a product includes a web server (12), a database server (14), and a database (16). The web server is connected to the database server, which contains the database. The web server stores a number of software function modules for receiving and processing data from the client terminals, and for returning results to the client terminals after processing. A related method is also provided.