This article underscores the importance of Sino-Korean vocabulary education for Vietnamese, whose mother tongue belongs to the Chinese character cultural area. This aims to make full use of the knowledge of Vietnamese learners` mother tongue for the education of words loaned from Chinese characters, which account for a majority of the Korean vocabulary. We began with a study on the characteristics of Sino-Vietnamese words, which were then compared with similar Sino-Korean words to identify the similarities and differences between these 2 groups, thus helping to find a better way for the education of Sino-Korean. Similarities and differences in phoneme, form and meaning found in the study indicated the possibility of using learners` knowledge of their mother tongue in the learning of Sino-Korean. As loaned Chinese characters are assimilated and read under the specific phonemic system of each language, it`s difficult to recognize their phoneme form. With an effort to understand how Vietnamese people recognize Chinese words in the Vietnamese language, we realized that Vietnamese people learn Chinese characters as part of the Vietnamese vocabulary and they have the ability to recognize Sino-Vietnamese words. Although a comprehensive system has not yet been in place, there are some tips to recognize Sino-Vietnamese words thanks to elements such as phoneme, form and meaning. So, the recognition of Sino-Korean through Sino-Vietnamese is quite possible. Although similarities and differences in the areas of form and meaning will definitely have an impact on the learning process, we want to first focus on phoneme with the introduction of a method to divide the phoneme of Sino-Korean words into initials and rhymes, which are then compared with the Vietnamese language in order to create a list of representative phonemes for learners. We hope that this contrastive study will be extended in the future and will be useful not only for Vietnamese learners of Korean but also Korean learners of Vietnamese.