The nature of deaths occurred at sea may be revealed the differences from that in the land, but there is no comprehensive statistical analysis of deaths occurred at Korean Sea so far. Therefore, the cases of deaths or missing in the period 1993 - 2006 were analyzed by the cause, place of death, and results of preliminary investigation. In the period from 1993 to 2006, over 1000 peoples were died or missing every year. The cases of marine safety accidents including self-carelessness and mishap were approached over 60% and cases of homicide were less than 1%. The closure cases of preliminary investigation were reached over 70% and the most of deaths occurred in fishing vessels (the range of 20 ~ 99 tonnage). The suspension cases of preliminary investigation were reached to 70% of all missing and drowning cases. The results showed that the most of deaths occurred at sea could be prevented by the safety regulations including mandatory report of accidents, marine safety education and training, punishment the people responsible for the accidents. For the unidentified bodies, data should be collected and recorded for the future identification. The crime scene investigators should be trained to ensure the quality of their professional skills regularly.