In this study, we proposed exploratory leaning on the theme of the sea. We planned linking Period of integrated Study with subject study.As a result,we guess that the following three points were suggested. (1)By learnig exploratory with the theme of the sea,children is able to connect with local experts. (2)By focusing on the SDGs and devising the arrangement of activities,the children has a sense of ownership of the sea and became interested in marine resources and the marine environment. (3)By linking Period of integrated Study with subject study,children were able to deepen their learning in terms of collecting information and utilizing acquired skills, etc.