This paper tried to discuss the quality of life (QOL) ranking of cities in Taiwan. Although there were many articles and researches have done a lot of contributions with this topic, we collect many indicators from previous researches but using exploratory data analysis (EDA) method instead. The tool we are using is GAP (Generalization association plot). We tried to decrease the indicator dimensions of QOL and get the cluster analysis of cities for data mining purpose by using GAP(Generalized association plot) . We demonstrate the fact that some of the indicators revealed good or bad performance of QOL among cities in Taiwan in different aspects. We even also explore the most similar pattern of city with a specific target city for analysis and discussion.