The present invention provides a radio frequency identification (RFID) system and a tag counting ending method for anti-collision thereof. The RFID system comprises a reader-writer and tags. The tag counting ending method comprises: in the counting process, when the reader-writer does not receive a response signal from a tag and the value of a register is not greater than a pre-determined counting ending register threshold value, the reader-writer transmits a Finish command to each of the tags and waits for responses; after receiving the Finish command, the tag determines whether the tag itself is counted successfully, if so, makes no response; if not, sets the counter of tag itself as 0 and transmits a response signal to the reader-writer; if the reader-writer receives the response signal, then determines that counting is not finished and continues to count the tag which makes response; if the reader-writer does not receive the response signal, then determines that counting is finished.