Abstract: There is a long cultural history both in China and Japan. and there are many cultural images with the same origin, and mermaid is one of them. According to the research, the earliest record of mermaid came from China's “The Classic of Mountains and Seas”, which was later introduced to Japan. With the changes of the times, the mermaid images of the two countries have gradually shown different characteristics based on the combination of local culture. Especially in the Qing Dynasty of China and the Edo period of Japan, the mermaid images of the two countries are relatively rich and complete, and fully retain local cultural characteristics, which have a certain degree of typicality and representativeness. Based on the previous studies on the mermaid image, this article focuses on comparing the similarities and differences between the mermaid image in the two periods of Chinese and Japanese culture, and explores the cultural reasons behind it.