The article describes the method defining 5 alleles of ABO blood group typing system by molecular hybridization in hydrogel oligonucleotide microchip. The testing points were SNP variants in positions 261 and 297of exon 6 and in positions 646 and 657 of exon 7. Therefore, 5 ABO blood groups can be easily revealed: A, B, 0(1), 0(1v), 0(2). The method was tested on 10 DNA samples isolated from blood and saliva of unrelated individuals. The results were confirmed by sequencing of the identified allelic fragments. Estimation sensitivity was 25 pg of total DNA input. This technique is cost-effective and easy for use and, therefore, promising for forensic-medical personal identification.