This research uses the DEA method to estimate and identify the sources of the index of Taiwan’s Happy Cities from 2014 to 2015. The productivity index shows that there is 0.542% decreased for the index of Taiwan’s Happy Cities in the research period. The major reason is that the EFFCH efficiency is decreased. The five top cities or counties with the highest tfpch index of Taiwan’s Happy Cities are Chiayi County, Chiayi City, Yilan County, Keelung City and Pingtung County.