This essay is a comparative study on the cognitive semantics of semantic features between Chinese-Korean Idioms. Idiom does not completely follow the meaning of its component, it`s the combination of transferable words. For the purpose of this thesis, I defined concept of idiom from the cognitive semantic point of view. Idiom are not only that the meaning of idiom can not be composed of its words meaning, but also that the meaning of idiom can be composed of its words meaning which are motivated. I prescribed that sematic properties of Chinese and Korean idioms are compositionality of idioms meaning, figurativeness of idioms meaning, and degreed of idioms meaning. From the comparison and analysis of semantics between Chinese and Korean idioms, it can not only demonstrate the features and relationship between Chinese and Korean idioms, but also provide the fundamental reference for translation, and provide the theoretical basis and priciple for Chinese idioms education and dictionary edition.