Objection To develop an oligonucleotied chip for genotyping of ABO blood group.Methods The genomic DNA in standard blood samples was extracted by phenol-chloroform method.A pair of primers were designed according to the seguences of exon 6 and 7 of ABO locus.The corresponding seguences were amplyfied and the PCR products were labeled by Cy5-dCTP.The group-specific probes were designed and immobilized on DNA chips which were made by APS-PDC method.The labeled PCR products were hybridized with the probes ard the signals were scanned by scanner and analyzed by Imagene softwale.Results One hundred of samples which ABO blood group were known were determined by the oligonuleotide chip and both the accuracy and sensitivity were satisfied.Conclusion DNA chip is available for genotyping of ABO blood groups.Compared to other methods it is more sensitive and intuitionistic and has advantage of integration.