A charge pump circuit includes N boosting circuits, (N−2) switching circuits and a control circuit. A kth boosting circuit includes a unidirectional component and a capacitor. A positive terminal of the unidirectional component of the kth boosting circuit is electrically connected to a negative terminal of a unidirectional component of a (k−1)th boosting circuit. A first terminal of the capacitor of the kth boosting circuit is electrically connected to a negative terminal of the unidirectional component of the kth boosting circuit. A (2i−1)th switching circuit selectively conducts a current path from a (2i−1)th boosting circuit to a first clock terminal or to a ground terminal according to a control signal of the control circuit. A (2i)th switching circuit selectively conducts a current path from a (2i)th boosting circuit to a second clock terminal or to the ground terminal according to the control signal of the control circuit.