A flush system includes a valve body, a valve seat, a flushing shaft and a flush water control arrangement which includes a flush actuator and a water control pusher. The flush actuator is adapted to move between a high and a low volume actuating position. The water control pusher includes a low and a high volume pusher member spacedly extended from the flush actuator, in such a manner that when the flush actuator is moved to the high volume actuating position, the high volume pusher member is driven to move to pivotally move the flushing shaft at the higher pushing position for producing a high volume of flush water, wherein when the flush actuator is move to the low volume actuating position, the low volume pusher member is driven to move to pivotally move the flushing shaft at the lower pushing position for producing a low volume of flush water.