This study was aimed to establish one tube PCR reaction technique to determine ABO blood group genotypes. Salting-out method was adopted to extract genomic DNA; one tube polymerase chain reaction with GeneScan technique was used to identify ABO genotypes. The results showed that the ABO genotypes of 132 samples were in accordance with the phenotypes determined by serological technique. The frequencies of A, B and O were 0.205, 0.159 and 0.636 respectively. AA, AO, AB, BB, BO and OO genotypes were 8 (6.1%), 31 (23.5%), 7 (5.3%), 6 (4.5%), 23 (17.4%), and 57 (43.2%) respectively. It is concluded that one tube polymerase chain reaction with GeneScan technique can determine the genotypes of ABO blood group.