A novel dual-mode ac signal processing integrated chip for urinalysis is proposed. Electrochemical impedance spectroscopy (EIS) analysis method is adopted in this chip. Compared with other electrochemical detection methods such as cyclic voltammetry (CV), the EIS required detection time is shorter. In addition, its circuits can be directly and effectively integrated into a chip, because the input, output, and measured signals are all electrical signals. The presented chip consists of the entire front-end input processing circuits and the sensing circuits of the bio-sample detection system. The input signal can be converted into either constant current or voltage ac signals for measuring the impedance of bio-sample. The magnitude and phase signals are measured to detect the concentration or other characteristics of the targeted bio-molecular.