In order to enable the language learners, the Korean and Chinese, have a comprehensive understanding of the adjectives, the author summarized the differences and relationships between the Korean and Chinese adjectives such as morphology, syntax after lots of reading and research. The subjects are summarized as followed: All the adjectives can be divided into the single, derived and compound adjectives in morphological aspects, in addition, the reiterative forms of the adjectives, which formed by repeating the root, are used to enhance and emphasis the meaning in both languages. In syntax the adjectives can appear as a predicate, modifiers, adverbial, subject and object in the articles, and the same adjective can have two or more than two grammatical function in the different articles, this phenomenon is known as the common or combination of the adjectives. Korean belongs to the agglutinative language and the Chinese is isolated language, therefore, there are much more differences compared with the same points. Firstly, Korean has a wealth of affixes, thus forming a large number of derived adjectives. There is no simply affixes in Chinese; only similar and lively type affixes exit. In Korean the suffix can restrict the meaning of the root, and also change the part of speech of the root. There is no such functional suffix in Chinese, but the prefix has the above-mentioned function. Secondly, in Chinese compound adjectives can form by combining the adjectives and object, but this type adjectives are undetected in Korean. In Chinese part of the adjectives can take an object, or even an adjective with two objects. This is obvious difference between the Korean and Chinese. Thirdly, in Korean the reiterative adjective can form only by repeating the single type root words, in Chinese the reiterative adjectives are divided into single and double syllable reiteration and the reiteration exits a variety of forms. Fourth, the another point is the various changing ending in Korean, but in Chinese, an isolated language, the word can not change the form; the grammatical functions of adjectives primarily is determined by the position of adjectives in the article. Korean adjectives can be expressed as a variety of tense when the ending changes. The Chinese adjectives can not express the tense even with the dynamic postposition, only express result and state after thing changed. The last, in Korean and Chinese, there is a fundamental difference in the negative form of adjectives. There are short and long-types negative sentences by using negative adverbs or supporting words, and the short-type negative sentences have many constraints in Korean. However, only short-type negative sentence, which used "不" and "没", exits in Chinese. The similarities and differences of Korean and Chinese adjectives are summarized basis on the analysis and compare of their morphology and syntax. This work will not only benefit both countries language learners to understand the relationship and differences between the two different languages, but also can provide the useful help to the language education.