Extension strategy tactics planning (ESTP), based upon the science of Extenics, is established for the purpose of solving contradictory problems. In this paper, the fundamental thoughts, theories and methods of ESTP are introduced concisely. The highlights of ESTP are that the techniques, used in the case of tackling such problems as how to generate the ideas of strategy tactics planning, how to completely analyze the resources, how to exploit extension resources, how to transfer the incompatible into the compati ble, and how to transfer the opposite into the co existent, are developed in a formalized way. And regarding the practices of ESTP, the applications of ESTP in resource integration, project, market development, and the prevention and handling crises are presented. Based on the science of Extenics, is established for the purpose of solving contradictory problems. In this paper, the fundamental thoughts, theories and methods of ESTP are conc conclyly. The highlights of ESTP are that the techniques , used in the case of tackling such problems as how to generate the ideas of strategy tactics planning, how to completely analyze the resources, how to exploit extension resources, how to transfer the incompatible into the compati ble, and how to transfer the opposite into the co existent, are developed in a formalized way. And regarding the practices of ESTP, the applications of ESTP in resource integration, project, market development, and the prevention and handling crises are presented.