In this research work, the main task is to increase the DC open loop gain of a CMOS operational amplifier for biomedical applications. It involves three basic concepts, theoretical calculation, design, simulation, and verification using CADENCE Allegro SPB and OrCAD Capture software. Our research work on the CMOS op amp circuit for biomedical applications achieved a DC open loop gain of 133.33dB and a PD of 0.07891mW, which could make it appropriate for biomedical applications that oper ate with small DC voltages. Key Words: Open Loop Gain, CMOS Op Amp, Biomedical Applications , CA DENCE Allegro SPB and OrCAD Captue softwar