This study aims to examine factors affecting the seafood processing business of primary cooperatives. For this purpose, I divided primary cooperatives that participate to seafood processing business into three group by sales scale. And then analyzed survey results for the four items that might be affecting the seafood processing business, type of seafood processing methods, HACCP certification status, distribution channels, processing difficulties during project implementation, etc. The result offers four implications. First, It is desirable to reduce the burden of the initial investment by leveraging the consignment process at the initial entry to seafood processing business. Second, HACCP certification is essential factor in order to promote seafood processing business as a long-term economic business. Third, To the steady growth of the seafood processing business, it is important to secure fixed large customers, as well as a individual customer. Fourth, For the continued growth of the seafood processing business it should be approached differently by way of sales, when the National Federation of Fisheries Cooperatives support to primary cooperatives.