This study is to survey the Japanese investigations for Korean sea during Meiji period. Meiji government was eager to develop new fishing ground to provide the marine products to their people, to offer the job for their people and to accumulate the starting capital. They found that the Korean sea was abundant in shark, sea cucumber and ear shell. These products were valuable for Chinese foods. From 1870's, Japan Navy investigated Korean sea for military purpose and subsequently for fishery. The first investigation for Korean maritime products was The Circumstances for Catching Fish in Korean Sea by Sekizawa Akikiyo in 1893. He was the most famous specialist in fishery and insisted that Japanese fishermen must go to Korean sea and catch fishes. Meiji government accepted his opinion and pushed the policy sending fishermen to Korean sea. Meiji government enlarged the investigations and backed up the activities of fisherman and the organization for fishery in Korean sea. Especially, the investigations by The Association for Korean Sea Fishery were repeated and detailed(1897~1900). The Association intervened the conflicts between Korean and Japanese fishermen. At the same time, The Association investigated the attitudes of Korean people to Japanese. The Guidelines for Fishery in Korean Sea by Kuzuu Syuzo was also very detail, especially in the kinds of fishes in Korean sea. These investigations were supported by Meiji government or organizations helped by government.