This article studies on a medical dictionary from Hong’s Diagnose and Secret Prescriptions with a Medical Dictionary (《洪家定診秘傳附醫書字 典》, <with A Medical Dictionary> for short, published in 1955). And a tentative research is made on these aspects, such as, the social history background of the book, the construction of the dictionary, the features of the dictionary, the selection of the Chinese characters and the explaination features the of characters, the meaning and value of the dictionary. This dictionary is high medical professional. And the characters has more paraphrases and the paraphrases have more correlationship with the medical. Thus, he dictionary has a big progress in the history of Korea Traditionary medical dictionary.