Abstract: Mismatch models to fit new process have become particularly urgent with MOS devices feature size are scaled to nanometer scale due to the importance of MOSFET exact match for the final performance of analog and mixed ICs.This paper utilizes an improved alpha-power-law to fit 65nm MOS model data and extract related process parameters.In comparison with BSIM4 model data, the relative average error and standard deviation is 1.70% and 8.26 respectively, then a simplified 65 nm MOSFET mismatch model for calculating standard deviation is presented based on this improved model and POV expression.The experimental results show that the relative average error and standard deviation is 7.69% and 10.49% respectively between this mismatch model and Monte-Carlo simulation data, this indicates that the proposed 65nm mismatch model is simple, effective, and accurate.