A sampling circuit for sampling a signal input includes a signal generation circuit, a sampling switch and a control circuit. The signal generation circuit is arranged for generating a first control signal. The sampling switch has a control node, and is arranged for determining a sampling time of the signal input according to a signal level at the control node. The control circuit is arranged for controlling the signal level at the control node, wherein when the signal level at the control node corresponds to a first level, and before a signal level of the first control signal is changed in order to adjust the signal level at the control node to a second level, the control circuit couples the first control signal to the control node.