Abstract: The distribution of ABO blood group from nine nationalities was reported. They may be divided into three groups: 1.B>O>A>AB. Han and Hui nationalities belong to this group. 2.0>B>A>AB. It was found in Mongolian, Ewenke. Elunchun, Korean, Russian and Man nationalities. 3.B>A>O>AB. Only Daur nationlity has this characteristic.
The genetic frequency r(0) is higher in Ewenke (0.7549), lower in Daur (0.5234) and Hui (0.5171) nationalities, p(A) is lower in Ewenke (0.1138), higher in Korean (0.2277) and Daur (0.2253), q(B) is higher in Hui (0.2818), lower in Ewenke (0.1313) and Korean (0.1753).
Comparing with the same nationality living in other parts of China, obvious difference was found only in the same nationality of Elunchun or of Ewenke.

Key words: Erythrocyte blood group; Gene frequency; Nationality; Inner Mongolia