This paper is based on the perspective of cognitive linguistics, and discusses the path of its semantic extension with the Body- Part Terms ‘Eye’, between Korean and Chinese. Its main contents are as follows. First, semantic extension based on conceptual metaphors. The morphological features of ‘eye’ in Korean language are projected into other fields to generate metaphorical meaning, but the scope of this kind of projection is limited. On the contrary, the morphological features of Chinese ‘eye’ is projected in a wider range and is more abundantly expressed. In addition, in Chinese, the importance of the eye in the body organs is projected to other fields. The ‘eye’ is metaphorically referred to as the ‘key of the thing’, but in Korean, ‘eye’ does not have this projection. Second, semantic extension based on conceptual metonymy. In its metaphorical meaning, the function of the eye plays a leading role, and the ‘eye’ extension formed on the basis of metonymy has much in common between Chinese and Korean. The biggest difference is that in the Chinese language, the overall features of the ‘eye’ can be used to quantify objects and refer to the units that measure ‘wells’ and ‘caves’, resulting in ‘grammatical metonymy’. In Korean, ‘eye’ does not have such semantic extension. Third, the interaction between metaphor and metonymy in the process of conceptualization of the eye. Based on the metonymic meaning of the body word ‘eye’, the conceptualization of entity metaphor, container metaphor and time metaphor is embodied in both Korean and Chinese. These conceptualization comes from the body experience that the eye can recognize. In other words, the basis of these conceptualization is the sense organ refers to the sensory experience. The eye is conceptualized as ‘entity’, ‘container’, ‘time’, reflecting the common physical experience of the Korean and Chinese peoples through metonymy embodied in the basic level of language and cognition, and due to metaphor and The interaction of metonymy forms a more complex and abstract concepts.