To provide a method for estimating a race or a birthplace by difference in the base sequence of nucleic acid of an organism, a virus, etc., with which a human is infected.

An organism or a virus with which a human is infected has evolved with the human population, however, the base sequence of nucleic acid of an organism or a virus is exceedingly shorter than that of human, has a smaller variation than that of human, a clear difference is confirmed in a nucleic acid sequence dependently on a human group and an area (called genome type). (1) The nucleic acid of an organism or a virus with which a human is infected is detected but not that of human and (2) a race or a birthplace is estimated by using the fact.