In this paper, a nonlinear mathematical model of modern regenerative MGT (micro gas turbine) with superior accuracy is developed. The regenerator can improve efficiency and slow dynamic response of MGT. In view of its significant influence on MGT performance, the average static and dynamic model of the regenerator is included. In order to get more accurate mathematical description for off-design condition performance characteristic of compressor and turbine, nonlinear analytical expressions of compressor and turbine are employed instead of polynomial approximate expressions. The specific expressions of nonlinear state space equations are deduced in this paper. Static simulation results prove the correctness and validity of the model. In this paper, the new model is adopted to analyze dynamic characteristic of MGT having regenerator. The new nonlinear model can be used to thoroughly study performance characteristic of MGT and design superior nonlinear controller. (C) 2015 Elsevier Ltd. All rights reserved.