These studies were focused on second and third industry, cluster of aquaculture was rarely explored and reported. Using Location Quotient and Spatial Gini Coefficient methods, the cluster of lefteye flounder Farming Industry of China from 2003 to 2012 was estimated and in this paper. The results showed that industrial cluster does exist in flounder aquaculture of China, mainly clustered in Shang Dong and Liao Ning. Its cluster degree in Shang Dong has been highest since the development of this industry, but it has decreased since 2005. Contrarily, its cluster degree in Liao Ning has kept on increasing. This study suggest that: the industry cluster of flounder aquaculture is influenced not only by resource endowments and demand factors, but also by technological innovation and industrial policies; if one want to promote the industrial clusters of this industry, industrial policy and technological innovation should be paid more attention, at the same time, industrial culture, which can help to create demand and lead the development of this industry, should be forged.