With the Defense Logistics policy adjustments and the financial resource of the industry is expanding. Resulting in the private industries has ability to participate in improving the defense industry development and supporting for the military weapons maintenance. Now we need to integrate with the technology of private industry and the method of business management in the National Defense Logistic Maintenance. Then a modernistic and independent national defense force will be established. This thesis includes two stages. The first stage is to apply the experience of Military Aircraft Outsourcing Maintenance and Outsourcing Theory. Then we set the decision standards and key factors of the Military Aircraft Outsourcing Maintenance. The second stage is to use Delphi Method to collect the experts' opinions for the military aircraft outsourcing maintenance. The outcomes will help us to understand the important sort for the key factors. This method can provide decision systematically makers analytic approach. The results can be set as a policy reference for the military aircraft outsourcing maintenance of the Air Force.