As global climate concerns about climate change and the environment become increasingly important, it is predicted that the efforts to increase the temperature and pressure of coal-fired power plants to increase their efficiency will be further received the spotlight. So high-efficiency coal-fired power plants based on Advanced-Ultra supercritical pressure (A-USC) are expected to adopt mainly in power plants adopting CCS in developed countries. It is anticipated that the existing low efficiency coal-fired power plant will be retrofitted in developing countries such as China and India. We will analyze the technology development trends of developed countries for A-USC power system and review the technology development plan of Korea.