Abstract: The provider of last resort (PoLR) service mechanism is an important part of the stable operation of the electricity retail market. With the comprehensive liberalization of China’s electricity retail market, it is urgent to deeply study the design connotation of the PoLR service mechanism in typical national electricity markets, and to design a PoLR service mechanism that adapts to the development of China’s electricity retail market. Firstly, this paper analyzed and compared the design of PoLR service mechanism in three typical electricity markets: the United Kingdom, Australia and Texas of the US, including the start of PoLR service, the selection of PoLR provider, the price mechanism, the cost recovery mechanism and the service period, etc. Then, it investigated the practice of China’s PoLR service mechanism, and analyzed the characteristics of China’s PoLR service mechanism based on other country’s experiences. Finally, based on the experience of typical countries and the reform environment of China's electricity retail market, relevant suggestions are put forward for the design of China's PoLR service mechanism.