The present invention discloses a hybrid power line/wireless appliance automation system for interfacing between at least one electric power distribution circuit and at least one electronic device, a power line communication device, and a power monitoring method using the same. Each power line communication device can be communicatively interconnected via power line communication and/or wireless communication. A threshold value of each power line communication device is dynamically adjusted by a host device via wired or wireless connection, so as to determine whether to continuously supply or turn off power to an electronic device coupled to the power line communication device. The present invention may be implemented/integrated to existing household electric power network without the need for additional physical data network infrastructure/lines, therefore is suitable to be applied in an intelligent home management system.