Design of very large scale analog integrated circuit (analog VLSI) is very much complex and requires much compromising nature to achieve application specific objective. With maximizing the efforts to reduce power consumption and to reduce W/L ratio, the analog integrated circuit industry is constantly developing smaller power supplies. Now days, challenges of analog integrated circuit designer are to make block of small power supplies with little or no reduction in performance. The CMOS OTA is designed in 25.5nm CMOS technology with 1.0V power supply to observe the configurations. In design of CMOS OTA TANNER EDA TOOL is used. Coding and simulation is done in T-Spice and layout is prepared in L-Edit. D.C analysis, A.C analysis, slew rate and analysis of transient response have been done in T-Spice. Waveforms are observed in W-Edit.