Abstract-TMED (transmission mounted electric device) PHEV(Plug-in hybrid vehicle) powertrain consist of engine, engine clutch, motor, transmission ,differential gear, wheel and tire. By disengaging engine clutch, the vehicle can use only motor power for driving. After battery depleted, engine and motor are cooperate to increase engine efficiency. In this paper, diesel PHEV(Plug-in hybrid vehicle) powertrain dynamic equations was derived from longitudinal vehicle model. In order to design optimal powertrain capacity in given specifications, various capacities of engine and motor model was derived from commercial engine and motor test data. Engine and Motor model use input signal and input shaft speed to calculate torque outputs, also calculate energy conversion efficiency. Using MATLAB Simulink program, diesel PHEV dynamic model was created from engine and motor model, and powertrain dynamic equations. Using developed simulator, we analysis basic performance of diesel PHEV.Index Terms-Diesel plug-in hybrid, vehicle dynamics, vehicle performance analysis.