This research applies the principal component analysis through categorized evaluation of statistical data on air quality and related meteorological parameters in central Taiwan. With that, the relationship and characteristic between air quality and meteorological parameters are anatomized. PSI values are categorized through the characteristics of air quality, meteorological parameters, and synoptic weather patterns. From the inspection of each meteorological parameter and each factor -loading value of principal components, principal component represented characteristics pollution condition can be explained by the ventilation index, the photochemical factor, the combustion source, the stability level and the wind speed. Furthermore, this study also categorizes the characteristics of dominant meteorological parameters at different air quality conditions under various synoptic weather patterns.