The main task of this research is to enhance the gain of a two stage CMOS operational ampli er by using current bu er technique It involves three basic concepts, theoretical calculation, design, simulation, and veri cation using CADENCE OrCAD PSPICE Design and Simulation software, which is based on analog and digital electronic devices and advanced integrated circuit design fundamentals. Our work on the two stage CMOS op amp circuit using the current bu er technique tried and achieved an increased DC open loop gain with a reduced power consumption.The two stage CMOS op amp design was operated at 2.5V power supply using 0.35 m CMOS technology and was found to exhibit a DC open loop gain of 130.334dB and a PD of 0.214mW, which could make it appropriate for medical device applications and other DC-operated portable devices