This paper presented the design of a novel embedded bio-impedance analyzer based on digital auto-balancing bridge method. The hardware architecture of the system mainly consists of FPGA, ADC, DACs, USB controller and so on. Many DSP algorithms such as direct digital synthesis, digital phase sensitive demodulation, digital modulation and digital filter were implemented in FPGA to realize the auto balancing function of the bridge circuit. Simulation results show that the system has good performance from low frequency up to 10 MHz. For the advantages of cost-efficient and high stability, it is suitable for BIA application.