Our previous study demonstrated that the oral administration of Juzen-taiho-to resulted in a significant inhibition of the liver metastasis of colon 26-L5 cells as compared with the untreated control, without side effects. We attempted to investigate the relationship between the HPLC pattern (referred to as the fingerprint) of the formulation and its component crude drugs and the inhibition of tumor metastasis in order to obtain the optimal efficacy and constant quality of the formulation. Two Juzen-taiho-to formulations (batches #1 and #2), which were individually prepared using the same 10 crude drugs and the same preparation procedure, showed similar anti-metastatic effects and absorbance patterns by HPLC analysis. Some variant formulations of Juzen-taiho-to, in which one crude drug was substituted with other crude drugs from different sources or places of origin, exhibited reduced efficacy as compared with the original formulation, as well as differences in the fingerprint pttern compared with the original formulation. Juzen (Naimo-Ogi→Kibana-Ogi), a variant formulation with the substitution of Astragali radix of a different origin and place of harvest, showed significant inhibition of the liver metastasis of tumor cells and a HPLC fingerprint pattern similar to that of the original formulation. Thus, HPLC fingerprint analysis of Kampo medicines may provide a useful basis for obtaining their optimal efficacy as well as constant quality of the formulation, although it has some problems and limitations, such as detectability by and sensitivity to UV absorbance.