This project aimed to characterize copepod community in the Izu Ridge region off Japan. Zooplankton samples were collected at 0-200 m using NORPAC net, and both DNA and RNA were extracted. After cDNA was synthesized, massive sequence data of 28S D2 region were obtained from both DNA and RNA (cDNA). Copepod communities were compared between the Izu Ridge and region off the ridge in order to identify key copepod species and their responses to complex environments in the Izu Ridge.