OBJECTIVE： To provide reference for the classification of the specification grade of Dioscorea opposite. METHODS： Using the Delphi method， 17 experts， who were associated with the study of the distribution and clinical application of D. opposite， were selected to conduct two rounds of consultation on 18 samples of medicinal herbs. The importance of the sensory evaluation indexes of D. opposite was screened and the overall satisfaction was evaluated. The specification grade of D. opposite was determined preliminarily. RESULTS： Totally 17 questionnaires were issued for each round of consultation， and 17 were recovered with recovery rate of 100％. According to statistical analysis， the average value of expert’s authority coefficient was 0.77±0.07， and average recurrence rate of individual review was （91.18±7.64）％. The average recurrence rates of group review in two rounds of consultation were （66.67±13.50）％ and （65.97±14.01）％ . The influence of working life， business background and educational background on recurrence rates of group review for interviewed experts was comprehensive. The full score ratio of appearance and cross-sectional characteristics importance was more than 80％， and the average value was more than 0.8. The full score ratio and average value of iron yam were higher. CONCLUSIONS： It is accurate and scientific to evaluate the specification grade of Chinese medicinal herbs with sensory experience. The most important evaluation indicators of D. opposite were the appearance， shape and cross-sectional characteristics. And it is divided into iron yam and non-iron yam preliminarily. The iron yam grade in descending order： Henan sandy iron yam， Shandong sandy iron yam， Henan loquat iron yam. The non-iron yam grade in descending order： Henan Huaiqingfu D. opposite， Hebei Xiaobaizui D. opposite， Hebei Ma D. opposite and Shanxi Chang D. opposite.