An automatic flushing system for toilet and an electronic bidet toilet having the same are disclosed. The automatic flushing system for toilet has as overflow passage connecting an overflow port of a tank or a vacuum breaker to a toilet bowl. The overflow passage includes a first overflow line having a first end fixedly connected to a tank overflow port and a second end fixedly connected to a rim outlet of the toilet bowl, and a second overflow line having a first end fixedly connected to a vacuum breaker overflow port and a second end fixedly connected to a jet outlet of the toilet bowl. According to the present utility model, the overflow problem of the water and vacuum breaker is solved and generation of bubbles in the vacuum breaker during overflowing is eliminated.