An object of the present invention is to provide a compound having a novel structure for overcoming the defects of conventional steroid agents and NSAIDs. It is found that the particular dihydroxy bodies of eicosapentaenoic acid and docosahexaenoic acid, which have not conventionally been known (11,18-dihydroxy eicosapentaenoic acid (11,18-diHEPE), 17,18-dihydroxy eicosapentaenoic acid (17,18-diHEPE) etc.), have activity of inhibiting neutrophil, thereby solving the object. The present invention unexpectedly remarkably inhibits infiltration into a tissue of, and activation of neutrophil found out at acute inflammation. The compound of the present invention is a compound which has not conventionally been known. Therefore, utility as a new therapeutic is provided.