Authors have investigated two national groups with different ethnogenesis. They are looking for the distribution of the blood group systems and Rh factor. German group consists of 207 and Arabian group - 359 adults (aged from 18 to 44). There are significant differences between two groups in ABO system (p<0,05) and Rh factor (p<0,001). The frequency of A and 0 blood groups in Germans is higher then in Arabs. Contrary B and AB groups are more frequent in Arabs. Negative Rh factor in Germans (20,29%) is over twice frequent then in Arabs (8.08%). The established data could be explained by different ethnogenesis, geographic and climate conditions.
