Objective To analyze the phenotype and genotype of one sample with ABO blood grouping discrepancies and to clarify the genetic mechanism. Methods The phenotype of the proband and his family were detected with traditional serological method,then PCR-SSP was carried out to identify the genotypes of the sample. Direct sequencing and cloning sequencing were performed to analyze the exons 6 and 7 DNA sequences. HLA typing and short tandem repeats were used to detect the genetic status among the family. Results T...