Abstract: This invention provides a device, method and system for implementing an echo control on hand-free phones, including an echo eliminator as a primary component. The method in use is listed as follows. First of all, local speech signals on a sending channel as well as remote speech signals on a receiving channel are sampled. Then call status of a current network is determined based on energy of the obtained remote and local speech signals samples. Finally, a corresponding echo control treatment to the speech signals traveling through the sending channel according to the resulting call status is given. As a result, the echo in a digital hand-free communication system can be efficiently eliminated.