A system for detecting wetness of article used by a care-receiver is provided, comprising: a radio frequency identity (RFID) tag to be attached onto an outer surface of an article used by the care-receiver, and a RFID reader. The RFID reader includes at least one first antenna module, a processor unit and a first wireless communication module. And the system further comprises a protective unit is configured for accommodating the RFID reader and buffering external pressure on the RFID reader to protect the RFID reader. The RFID reader is configured for being disposed on a back of a cushion. The first wireless communication module is configured to send a detection signal (excitation signal) through the first antenna module to the RFID tag and the processor unit determines the water content (%) of the article at the usage time (t) by using the RSSI(0) and RSSI(t).