Abstract: Optical fiber communication has been adopted widely in big-data era, which can satisfy the long-distance and high-capacity needs with characteristics of fast speed, wide bandwidth and high reliability. As the front end of optical receiver, optical receiver pre-amplifier determines the performance of the whole receiver system. Based on SMIC 0.13 m CMOS technology, a 5Gbps optical receiver pre-amplifier was completed in this work. At first, the full differential structure can eliminate the common-mode noise and reduce the input-referred noise. Then, in order to suppress the defect of large photodiode capacitance, Regulated Cascade(RGC) structure with low input impedance was exploited. The output buffer was realized with Common-Mode Logic structure that can balance the gain and bandwidth. The simulation results show the gain of 62 dB and bandwidth of 4.7 GHz. Meanwhile, the amplifier has a input-referred noise of 30.1 pA/Hz. The eye diagram is clear and the opening is enough big, which can meet the communication demand of 5 Gbps balance detector system.