Objective:To study the characteristics of the clinical application of traditional herbal medicine in five countries and regions where traditional medicine (TM) is widely used:Japan;South Korea;mainland China;Hong Kong,China;Taiwan,China.And to analyze,from multiple angles,the variations in the methods of TM used in each countries and regions.Methods:Fifty commonly used traditional herbs (TOPS0) from classical formulae were selected,and descriptive statistics,correlation analyses,and Friedman test were used to compare methods of clinical application and dosages in the countries and regions of interest based on a retrospective review of randomly-selected medical records.Results:There were significant differences in sequencing TOP50 among the five countries and regions (P ＜.01).The adherence to the classical formulae,from strong to weak was Japan;mainland China;Taiwan,China;Hong Kong,China;South Korea.There were also significant differences in TOPS0 dosing regimens (P ＜.01).Overall dosages of TOPS0 from high to low were:mainland China;Hong Kong,China;Taiwan,China;South Korea;Japan.Finally,there were significant differences in the dosage intervals (P ＜.01),with dosage intervals from maximum to minimum as follows:mainland China;Taiwan,China;Hong Kong,China;South Korea;Japan.Conclusions:The clinical dosages of traditional herbal medicine used in the mainland China are relatively large compared with those prescribed in the other four countries and regions,and the range of dosages in mainland China is more flexible.On the other hand,clinical dosages of TOP50 are the lowest in Japan,where the dosage range is also the narrowest,supporting the idea that Doctors of Kampo medicine are highly cautious and are likely to adhere strictly to classical formulae,while Hong Kong,China and Taiwan,China are in the middle.The dosage of TOPS0 in South Korea is significantly lower than that used in the mainland China;Hong Kong,China and Taiwan,China where the adherence to the classical formulae was the lowest,albeit slightly higher than that in Japan.The methods of clinical application of traditional herbal medicine in the five countries and regions were affected by multiple factors,including history,geography,climate,and culture.