A new method for cooling the micro gas turbine rotor was proposed. Using a hollow shaft, cooling air is actively induced into the rotor. To access the effect, CFD calculations were conducted. The rotor temperature of a micro gas turbine would be unacceptably high, because the compressor is placed nearer to the turbine by making the scale small. The heat flux from the turbine has great influence on deteriorating the compressor efficiency. As the results, some characteristic of flow fields and cooling performance were realized. This new cooling method has a great potential as a heat shield in a micro gas turbine.