The Study focuses on supplier selection criteria for develop long-term tactics cooperation. This is based on my working experience and otherpeople's studies to analyze and get those supplier selecting standards. We investigate the expert’s opinions about Modified Delphi Method and use the AHP toextract the critical criteria from questionnaires. The hierarchy Of the supplier selection and the weights of the criteria aredeveloped.Weverify the result by an actual example. The result provides manager the best supplier.