The study of ABO polymorphism has contributed to the understanding of human genetic diversity. The objective of our work is to determine the phenotypic and allelic frequencies of the ABO system in the population of the Algerian Northeast, and to make a comparative study with other national and world populations.

The study included 10,208 blood donors, originating from the Northeast of Algeria, the ABO grouping was carried out by serological techniques on plate and gel card, the comparison of the ABO allelic frequencies, and the genetic distances between the populations, were carried out respectively by using the R software, and the SPSS version 20 software.

The order of frequency of ABO phenotypes is O>A>B>AB, with respectively 46.32%, 33.47%, 15.93% and 4.28%, while the order of frequency of ABO alleles is O>A>B with respectively 0.6820, 0.2112, 0.1068. The estimation of the genetic distances between our study population and other national, North African and world populations, allowed us to observe that our study population is very close genetically to North African populations, and the genetic differences were less pronounced with sub-Saharan populations, than with European and Asian populations.

Our region has known multiple movements and population mixtures that have contributed to the genetic identity of our population, linked in part to its geographical location at the gateway to Africa, and on the southern shore of the Mediterranean, but also to several historical events such as invasions, trade, and Islamic conquests.