KiK-net is a strong motion network deploying with the high sensitivity seismograph network (Hi-net) by National Research Institute for Earth Science and Disaster Prevention (NIED). File format of KiK-net records follows the form of K-NET files. KiK-net stations have two tree-component accelerometers on the ground and at the hard rock layer in a borehole. Therefore six files with file extensions .ns1, .ew1, .ud1, .ns2, .ew2 and .ud2, are provided at a site for an earthquake. Further information and observed records are available at http://www.kik.bosai.go.jp/.