As an important concept in literary theory, imagery theory has undergone a long process of development. But there are different characteristics in ancient and modern times， western countries and China. Western imagery is more concerned with Xiang, whereas the Chinese classical imagery theory focuses on Yi，it argues that images are the unification of subjective feelings and objects. This paper mainly uses Chinese classical imagery theory to analyze ocean imagery. Based on the development of imagery theory, we firstly defined the definition of ocean imagery as follows: It is the visible phenomena associated with the ocean which can be utilized to describe, imply， express emotions and ambitions by the poets. Then we choose the wei jin, Northern and Southern Dynasties which is the turning point in the development of Chinese literature as our range of study and select the most closely related style of writing —— poetry as our transverse research center， take the electronic data library and paper literature as basic research data to make the detailed statistics and rough structural classification. In terms of basic meaning, it can be divided into seven categories： the first category is the imagery of the basic meaning generally refer to the sea； the second is the basic meaning of sea water and its existence； the third is the imagery of the basic meaning associated with the sea area； the forth is the imagery of the basic meaning associated with maritime life； the fifth category is the imagery of the basic meaning associated with marine organism; the sixth class is the image related to the ocean landscape; The seventh category of an imagery is related to marine myth or religion. In terms of structure, the ocean imagery can be divided into single and complex form. At last, we make the functional classification of ocean imagery based on the specific poems: descriptive ocean imagery, metaphorically ocean imagery and symbolic ocean imagery.