In order to establish the methods for DUS test in hosta (Hosta Tratt.), we investigated the phenotypic diversity at 19 quantitative traits in 76 varieties. The quantification period and tissue position for some phenotypic characters were analyzed. As a result, the width of petiole could be measured in its natural state, and the length of peduncle could be quantified from the base to the attach of first flower. The bracts of first flower were suitable as observation object for all characters of bract, and the 1st-3nd opening flower was optimal for quantitative traits about flower. All the candidate characters fulfilled the requirements of DUS testing and could be classified into 3 to 9 continuous grades. The characters in whole plants and the leaves could be measured at blossom, and the characters of inflorescence should be observed after the last flower opened.