Abstract: In order to fully stimulate the peak regulation willingness of thermal power units and promote the local consumption of clean energy such as hydropower, China Southern Power Grid pilots the first provincial peak regulation ancillary service market of the region in Guangxi, China. This paper focuses on the transaction types, transaction organization forms, clearing models and methods, settlement allocation mechanism, engineering problems and treatment methods of the peak regulation ancillary service market in Guangxi. The clearing model considers not only the conventional deep peak regulation and start-stop peak regulation resources, but also the dispatch of start-stop peak regulation of units on hot standby, which fully exploits the peak regulation potential of thermal power units. Meanwhile, the constraints consider the startup and shutdown processes of the units, which better matches with the actual peak regulation characteristics of thermal power units. The developed technical support system based on the proposed model and method has been put into the practical operation of the peak regulation ancillary service market in Guangxi.The case analysis and operation practice show that the proposed model and method are effective, and the developed technical support system can meet the actual engineering needs.