The accident statistics use the data from police accident reports and statistics. Although the official accident statistics are useful, they provide very limited information about how accidents occur, the cause of the accident and the injury mechanisms. This limitations could be overcome by carrying out the in-depth accident study and analysing investigations, collecting more detailed information. Meanwhile a net of in-depth investigation teams are operating worldwide, such as NASS (National Accident Sampling System) and CIREN (Crash Injury Research and Engineering Network) in US, OTS (On the spot investigation) in UK. In this study, the database structure and variables of Korea in-depth accidents investigation system would be proposed through considering the database structure of GIDAS (Germany In-Depth Accidents Study). GIDAS is one of the best system on the in-depth accident study system in the world. GIDAS was established in 1999 as a cooperation project between Federal Highway Research Institute of Germany (BASt) and research association on automotive engineering of German Car Industry(FAT). The iGLAD (Initiative for the Global Harmonization of Accident Data) was also considered to introduce into the database variables of Korea in-depth accident study. Current police reports were compared with GIDAS and iGLAD. To collaborate of the Worldwide in-depth accident data, this paper proposed that the database of Korea in-depth accident study would be introduced the structure of GIDAS and the core variables of iGLAD. Harmonization of the structures and core variables of Korea in-depth accident study will be better than the making unique ones. The database structure and core variables of KIDAS(Korea In-Depth Accident Study) introduced of GIDAS and iGLAD.