A power transmission system for a vehicle is provided. The system comprises an engine, a plurality of input shafts, at least one of the input shafts being configured to selectively engage with the engine, each of the input shafts being provided with a shift driving gear thereon, a plurality of output shafts, each of the output shafts being provided with a shift driven gear configured to mesh with a corresponding shift driving gear, a motor power shaft configured to rotate together with one of the input shafts, and a first motor generator configured to rotate together with the motor power shaft. When the motor power shaft rotates together with the one of the input shafts, the first motor generator uses at least a part of power output by the engine to generate electric power when the vehicle is parking or running. A vehicle including the power transmission system is also provided.