More than 160 MSW incinerators have operated in the United States since the early 1960s. About 75 percent of these incinerators use mass-fired technology with energy production systems, known as waste-to-energy (resource recovery) plants, similar to the Taiwanese plants. Because of the similarities, the experience gained at U.S. incineration plants may be applicable to the Taiwanese plants. This paper will discuss U.S. experience of mass-fired MSW incinerator testing and performance evaluation.