A method is performed by using a master smart scale with a master-slave mode, a remote communication device and a slave smart scale to manage multiple chemicals from a remote place. The master smart scale performs an initialization procedure to obtain an initial weight of one chemical; generate an identification information by reading a radio frequency tag of the chemical; use the identification information to inform the remote communication device to open an input page for users to input a basic information into the master smart scale; and mark the basic information and the initial weight with the identification information. In the master-slave mode, the master smart scale allows receiving the information of the chemical from its slave smart scale. For inquiry, a specific page is opened with the remote communication device to receive and display a statistical data generated from the master smart scale.