The study of homonyms shared in Chinese and Japanese have long been focusing on intermediate and advanced words made of Chinese characters and their meaning. Part of speech has not been included to provide the full picture and to be considered when it comes to Japanese learning. This study aims at uncovering the full picture of this category with words made of two Chinese characters as the main focus. It attempts to classify the words based on the relativities of their meaning and part of speech. According to the research on the meaning of words, approximately 40% are isomorphic words while homonyms also account for 10%. On the other hand, after studying their part of speech, it is found that most of the vocabularies have only one part of speech, with more than 60% in Japanese and 70% in Chinese. In addition, noun takes up the majority, with over 60% in both languages, followed by words that have verb's function and this group has more than 25%.After studying and comparing meaning together with part of speech, it is derived that half of the words are isomorphic synonyms (words share the same form and meaning) that also have equivalent part of speech. The other half is isomorphic synonyms either does not share the same part of speech or isomorphic words that have different meanings and/or have different part of speech. With the examination of elementary homonyms in Chinese and Japanese, native Chinese students can be benefited as this study identifies homonyms words that can be easily mistaken and need to be used carefully when learning Japanese.