An energy harvesting system including a novel front-end multi-stage rectifier (AC-DC) charge pump, a power management, low-dropout voltage regulator (LDO) and a battery charger is presented in this work. The designed circuit is realized by the TSMC 0.35um CMOS process. The proposed circuit system is suitable for harvesting the low-frequency vibration energy in portable medical sensors or low-power high-frequency RFID sensors. This rectifier charge pump leverages the input AC voltage to the multiples of the original input voltage without inductances adopted. Since the strength of the external energy source is not guaranteed to be consistent, a power management is also designed for ensuring regular operation on load device. Finally, an LDO and a battery charger are designed to complete the whole system. It is shown theoretically and experimentally that the proposed rectifier charge pump performs better than the conventional multiplexer in terms of efficiency with high load current.